Perl policy: Document major version upgrade trigger

[debian/debian-policy.git] / upgrading-checklist.sgml

<!doctype debiandoc system>

<debiandoc>
  <book> 
    <title> Policy checklist for upgrading your packages </title>
      <author> Bill Allombert <email/ballombe@debian.org/ </author>
      <author> Josip Rodin </author>
      <author> Julian Gilbey </author>
      <author> Russ Allbery </author>
      <author> Manoj Srivastava <email/srivasta@debian.org/

<chapt> About the checklist
<p>
The checklist below has been created to simplify the upgrading process
of old packages.  Note that this list is not "official"; it simply
gives an indication of what has changed and whether you are likely to
need to make changes to your package in light of this.  If you have
doubts about a certain topic, if you need more details, or if you
think some other package does not comply with policy, please refer to
the Policy Manual itself.  All of the changes from version 3.0.0
onwards indicate which section of the Policy Manual discusses the
issue: [3.4] means section 3.4.  The section numbering changed when
the packaging manual was incorporated into policy; the section numbers
used below refer to the current version.
<p>
Here is how the check list works: Check which policy version your
package was checked against last (indicated in the "Standards-Version"
field of the source package).  Then move upwards until the top and
check which of the items on the list might concern your package.  Note
which sections of policy discuss this, and then check out the Policy
Manual for details.  If you are upgrading from Policy version &lt; 2.5.0,
it may be easier to check through the whole of policy instead of
picking your way through this list.

<chapt> The checklist

<sect> Version 3.9.3.0
<p>

Unreleased.

</p><p><taglist>
<tag>5.6.8</tag>
  <item>The <tt>Architecture</tt> field in <file>*.dsc</file> files may
  now contain the value <tt>any all</tt> for source packages building both
  architecture-independent and architecture-dependent packages.
  </item>
<tag>11.8</tag>
  <item>The Policy rules around Motif libraries were just a special case
  of normal rules for non-free dependencies and were largely obsolete, so
  they have been removed.
  </item>
<tag>perl</tag>
  <item> Packages may declare an interest in the <var>perl-major-upgrade</var> 
  trigger to be notified of major upgrades of perl.
  </item>
</taglist></p>

<sect> Version 3.9.2.0
<p>

Released April, 2010.

</p><p><taglist>
<tag>*</tag>
  <item>Multiple clarifications throughout Policy where "installed" was
  used and the more precise terms "unpacked" or "configured" were
  intended.
  </item>
<tag>3.3</tag>
  <item>The maintainer address must accept mail from Debian role accounts
  and the BTS.  At least one human must be listed with their personal
  email address in <tt>Uploaders</tt> if the maintainer is a shared email
  address.  The duties of a maintainer are also clearer.
  </item>
<tag>5</tag>
  <item>All control fields are now classified as simple, folded, or
  multiline, which governs whether their values must be a single line or
  may be continued across multiple lines and whether line breaks are
  significant.
  </item>
<tag>5.1</tag>
  <item>Parsers are allowed to accept paragraph separation lines
  containing whitespace, but control files should use completely empty
  lines.  Ordering of paragraphs is significant.  Field names must be
  composed of printable ASCII characters except colon and must not begin
  with #.
  </item>
<tag>5.6.25</tag>
  <item>The <tt>DM-Upload-Allowed</tt> field is now documented.
  </item>
<tag>6.5</tag>
  <item>The system state maintainer scripts can rely upon during each
  possible invocation is now documented.  In several less-common cases,
  this is stricter than Policy had previously documented.  Packages with
  complex maintainer scripts should be reviewed in light of this new
  documentation.
  </item>
<tag>7.2</tag>
  <item>The impact on system state when maintainer scripts that are part
  of a circular dependency are run is now documented.  Circular
  dependencies are now a should not.
  </item>
<tag>7.2</tag>
  <item>The system state when <prgn>postinst</prgn> and <prgn>prerm</prgn>
  scripts are run is now documented, and the documentation of the special
  case of dependency state for <prgn>postrm</prgn> scripts has been
  improved.  <prgn>postrm</prgn> scripts are required to gracefully skip
  actions if their dependencies are not available.
  </item>
<tag>9.1.1</tag>
  <item>GNU/Hurd systems are allowed <file>/hurd</file>
  and <file>/servers</file> directories in the root filesystem.
  </item>
<tag>9.1.1</tag>
  <item>Packages installing to architecture-specific subdirectories of
  <file>/usr/lib</file> must use the value returned by
  <prgn>dpkg-architecture -qDEB_HOST_MULTIARCH</prgn>, not by
  <prgn>dpkg-architecture -qDEB_HOST_GNU_TYPE</prgn>; this is a path change
  on i386 architectures and a no-op for other architectures.
  </item>
<tag>virtual</tag>
  <item><tt>mailx</tt> is now a virtual package provided by packages that
  install <prgn>/usr/bin/mailx</prgn> and implement at least the
  POSIX-required interface.
  </item>
</taglist></p>

<sect> Version 3.9.1.0
<p>

Released July, 2010.

</p><p><taglist>
<tag>3.2.1</tag>
  <item>Date-based version components should be given as the four-digit
  year, two-digit month, and then two-digit day, but may have embedded
  punctuation.
  </item>
<tag>3.9</tag>
  <item>Maintainer scripts must pass <tt>--package</tt>
  to <prgn>dpkg-divert</prgn> when creating or removing diversions and
  must not use <tt>--local</tt>.
  </item>
<tag>4.10</tag>
  <item>Only <prgn>dpkg-gencontrol</prgn> supports variable substitution.
  <prgn>dpkg-genchanges</prgn> (for <file>*.changes</file>)
  and <prgn>dpkg-source</prgn> (for <file>*.dsc</file>) do not.
  </item>
<tag>7.1</tag>
  <item>Architecture restrictions and wildcards are also allowed in binary
  package relationships provided that the binary package is not
  architecture-independent.
  </item>
<tag>7.4</tag>
  <item><tt>Conflicts</tt> and <tt>Breaks</tt> should only be used when
  there are file conflicts or one package breaks the other, not just
  because two packages provide similar functionality but don't interfere.
  </item>
<tag>8.1</tag>
  <item>The SONAME of a library should change whenever the ABI of the
  library changes in a way that isn't backward-compatible.  It should not
  change if the library ABI changes are backward-compatible.  Discourage
  bundling shared libraries together in one package.
  </item>
<tag>8.4</tag>
  <item>Ada Library Information (<file>*.ali</file>) files must be
  installed read-only.
  </item>
<tag>8.6.1, 8.6.2, 8.6.5</tag>
  <item>Packages should normally not include a <file>shlibs.local</file>
  file since we now have complete <file>shlibs</file> coverage.
  </item>
<tag>8.6.3</tag>
  <item>The SONAME of a library may instead be of the
  form <tt><var>name</var>-<var>major-version</var>.so</tt>.
  </item>
<tag>10.2</tag>
  <item>Libtool <file>.la</file> files should not be installed for public
  libraries.  If they're required (for <tt>libltdl</tt>, for instance),
  the <tt>dependency_libs</tt> setting should be emptied.  Library
  packages historically including <file>.la</file> files must continue to
  include them (with <tt>dependency_libs</tt> emptied) until all libraries
  that depend on that library have removed or emptied
  their <file>.la</file> files.
  </item>
<tag>10.2</tag>
  <item>Libraries no longer need to be built with <tt>-D_REENTRANT</tt>,
  which was an obsolete LinuxThreads requirement.  Instead, say explicitly
  that libraries should be built with threading support and to be
  thread-safe if the library supports this.
  </item>
<tag>10.4</tag>
  <item><file>/bin/sh</file> scripts may assume that <prgn>kill</prgn>
  supports an argument of <tt>-<var>signal</var></tt>,
  that <prgn>kill</prgn> and <prgn>trap</prgn> support the numeric signals
  listed in the XSI extension, and that signal 13 (SIGPIPE) can be trapped
  with <prgn>trap</prgn>.
  </item>
<tag>10.8</tag>
  <item>Use of <file>/etc/logrotate.d/<var>package</var></file> for
  logrotate rules is now recommended.
  </item>
<tag>10.9</tag>
  <item>Control information files should be owned by <tt>root:root</tt>
  and either mode 644 or mode 755.
  </item>
<tag>11.4, 11.8.3, 11.8.4</tag>
  <item>Packages providing alternatives for <prgn>editor</prgn>,
  <prgn>pager</prgn>, <prgn>x-terminal-emulator</prgn>, or
  <prgn>x-window-manager</prgn> should also provide a slave alternative
  for the corresponding manual page.
  </item>
<tag>11.5</tag>
  <item>Cgi-bin executable files may be installed in subdirectories
  of <file>/usr/lib/cgi-bin</file> and web servers should serve out
  executables in those subdirectories.
  </item>
<tag>12.5</tag>
  <item>The GPL version 1 is now included in common-licenses and should be
  referenced from there instead of included in the <file>copyright</file>
  file.
  </item>
</taglist></p>

<sect> Version 3.9.0.0
<p>

Released June, 2010.

</p><p><taglist>
<tag>4.4, 5.6.15</tag>
  <item>The required format for the date in a changelog entry and in the
  Date control field is now precisely specified.
  </item>
<tag>5.1</tag>
  <item>A control paragraph must not contain more than one instance of a
  particular field name.
  </item>
<tag>5.4, 5.5, 5.6.24</tag>
  <item>The <tt>Checksums-Sha1</tt> and <tt>Checksums-Sha256</tt> fields
  in <file>*.dsc</file> and <file>*.changes</file> files are now
  documented and recommended.
  </item>
<tag>5.5, 5.6.16</tag>
  <item>The <tt>Format</tt> field of <file>.changes</file> files is now
  1.8.  The <tt>Format</tt> field syntax for source
  package <file>.dsc</file> files allows a subtype in parentheses, and it
  is used for a different purpose than the <tt>Format</tt> field
  for <file>.changes</file> files.
  </item>
<tag>5.6.2</tag>
  <item>The syntax of the <tt>Maintainer</tt> field is now must rather
  than should.
  </item>
<tag>5.6.3</tag>
  <item>The comma separating entries in <tt>Uploaders</tt> is now must
  rather than should.
  </item>
<tag>5.6.8, 7.1, 11.1.1</tag>
  <item>Architecture wildcards may be used in addition to specific
  architectures in <file>debian/control</file> and <file>*.dsc</file>
  Architecture fields, and in architecture restrictions in build
  relationships.
  </item>
<tag>6.3</tag>
  <item>Maintainer scripts are no longer guaranteed to run with a
  controlling terminal and must be able to fall back to noninteractive
  behavior (debconf handles this).  Maintainer scripts may abort if there
  is no controlling terminal and no reasonable default for a high-priority
  question, but should avoid this if possible.
  </item>
<tag>7.3, 7.6.1</tag>
  <item><tt>Breaks</tt> should be used with <tt>Replaces</tt> for moving
  files between packages.
  </item>
<tag>7.4</tag>
  <item><tt>Breaks</tt> should normally be used instead
  of <tt>Conflicts</tt> for transient issues and moving files between
  packages.  New documentation of when each should be used.
  </item>
<tag>7.5</tag>
  <item>Use <tt>Conflicts</tt> with <tt>Provides</tt> if only one provider
  of a virtual facility can be installed at a time.
  </item>
<tag>8.4</tag>
  <item>All shared library development files are no longer required to be
  in the <tt>-dev</tt> package, only be available when the <tt>-dev</tt>
  package is installed.  This allows the <tt>-dev</tt> package to be split
  as long as it depends on the additional packages.
  </item>
<tag>9.2.2</tag>
  <item>The UID range of user accounts is extended to 1000-59999.
  </item>
<tag>9.3.2, 10.4</tag>
  <item><file>init.d</file> scripts are a possible exception from the
  normal requirement to use <tt>set -e</tt> in each shell script.
  </item>
<tag>12.5</tag>
  <item>The UCB BSD license was removed from the list of licenses that
  should be referenced from <file>/usr/share/common-licenses/BSD</file>.
  It should instead be included directly
  in <file>debian/copyright</file>, although it will still be in
  common-licenses for the time being.
  </item>
<tag>debconf</tag>
  <item><tt>SETTITLE</tt> is now documented (it has been supported for
  some time).  <tt>SETTITLE</tt> is like <tt>TITLE</tt> but takes a
  template instead of a string to allow translation.
  </item>
<tag>perl</tag>
  <item><package>perl-base</package> now
  provides <package>perlapi-<var>abiname</var></package> instead of a
  package based solely on the Perl version.  Perl packages must now depend
  on <package>perlapi-$Config{debian_abi}</package>, falling back
  on <tt>$Config{version}</tt> if <tt>$Config{debian_abi}</tt> is not set.
  </item>
<tag>perl</tag>
  <item>Packages using <file>Makefile.PL</file> should use
  <tt>DESTDIR</tt> rather than <tt>PREFIX</tt> to install into the package
  staging area.  <tt>PREFIX</tt> only worked due to a Debian-local patch.
  </item>
</taglist></p>

<sect> Version 3.8.4.0
<p>

Release Jan 2010.

</p><p><taglist>
<tag>9.1.1</tag>
  <item> An FHS exception has been granted for multiarch libraries.
  Permitting files to instead be installed to <file>/lib/triplet</file> and
  <file>/usr/lib/triplet</file> directories.
  </item>
<tag>10.6</tag>
  <item>Packages may not contain named pipes and should instead create
  them in postinst and remove them in prerm or postrm.
  </item>
<tag>9.1.1</tag>
  <item><file>/sys</file> and <file>/selinux</file> directories are explicitly
  allowed as an exception to the FHS.
  </item>
</taglist></p>

<sect> Version 3.8.3.0
<p>
Released Aug 2009.

</p><p><taglist>
<tag>4.9</tag>
  <item>DEB_*_ARCH_CPU and DEB_*_ARCH_OS variables are now documented and
  recommended over GNU-style variables for that information.
  </item>
<tag>5.6.8</tag>
  <item>Source package Architecture fields may contain <em/all/ in
  combination with other architectures.  Clarify when <em/all/ and <em/any/
  may be used in different versions of the field.
  </item>
<tag>5.6.14</tag>
  <item>The Debian archive software does not support uploading
  to multiple distributions with one <file>*.changes</file> file.
  </item>
<tag>5.6.19</tag>
  <item>The Binary field may span multiple lines.
  </item>
<tag>10.2</tag>
  <item>Shared library packages are no longer allowed to install libraries
  in a non-standard location and modify <file/ld.so.conf/.  Packages
  should either be installed in a standard library directory or packages
  using them should be built with RPATH.
  </item>
<tag>11.8.7</tag>
  <item>Installation directories for X programs have been clarified.
  Packages are no longer required to pre-depend on x11-common before
  installing into <file>/usr/include/X11</file>
  and <file>/usr/lib/X11</file>.
  </item>
<tag>12.1</tag>
  <item>Manual pages are no longer required to contain only characters
  representable in the legacy encoding for that language.
  </item>
<tag>12.1</tag>
  <item>Localized man pages should either be kept up-to-date with
  the original version or warn that they're not up-to-date, either
  with warning text or by showing missing or changed portions in the
  original language.
  </item>
<tag>12.2</tag>
  <item>install-info is now handled via triggers so packages no
  longer need to invoke it in maintainer scripts.  Info documents
  should now have directory sections and entries in the document.
  Packages containing info documents should add a dependency to
  support partial upgrades.
  </item>
<tag>perl</tag>
  <item>The requirement for Perl modules to have a versioned
  Depend and Build-Depend on <tt>perl &gt;= 5.6.0-16</tt> has been removed.
  </item>
</taglist></p>

<sect> Version 3.8.2.0
<p>

Released Jun 2009.

</p><p><taglist>
<tag>2.4</tag>
  <item>The list of archive sections has been significantly expanded.  See
  <url id="http://lists.debian.org/debian-devel-announce/2009/03/msg00010.html"
  name="this debian-devel-announce message">
  for the list of new sections and rules for how to categorize
  packages.                                                
  </item>
<tag>3.9.1</tag>
  <item>All packages must use debconf or equivalent for user prompting,
  though essential packages or their dependencies may also fall
  back on other methods.                                   
  </item>
<tag>5.6.1</tag>
  <item>The requirements for source package names are now explicitly
  spelled out.
  </item>
<tag>9.1</tag>
  <item>Legacy XFree86 servers no longer get a special exception from the
  FHS permitting <file>/etc/X11/XF86Config-4</file>.
  </item>
<tag>9.1.3</tag>
  <item>Removed obsolete dependency requirements for packages that use
  <file>/var/mail</file>.
  </item>
<tag>11.8.5</tag>
  <item>Speedo fonts are now deprecated.  The X backend was disabled
  starting in lenny.                                       
  </item>
<tag>12.5</tag>
  <item>The GNU Free Documentation License version 1.3 is included in
  common-licenses and should be referenced from there.     
  </item>
</taglist></p>

<sect> Version 3.8.1.0
<p>

Released  Mar 2009.

</p><p><taglist>
<tag>3.8</tag>
  <item>Care should be taken when adding functionality to essential and
  such additions create an obligation to support that functionality
  in essential forever unless significant work is done.    
  </item>
<tag>4.4</tag>
  <item>Changelog files must be encoded in UTF-8.                
  </item>
<tag>4.4</tag>
  <item>Some format requirements for changelog files are now "must"
  instead of "should."
  </item>
<tag>4.4.1</tag>
  <item>Alternative changelog formats have been removed.  Debian only
  supports one changelog format for the Debian Archive.
  </item>
<tag>4.9.1</tag>
  <item>New nocheck option for DEB_BUILD_OPTIONS indicating any build-time
  test suite provided by the package should not be run.    
  </item>
<tag>5.1</tag>
  <item>All control files must be encoded in UTF-8.              
  </item>
<tag>5.2</tag>
  <item><file>debian/control</file> allows comment lines starting with #
  with no preceding whitespace.
  </item>
<tag>9.3</tag>
  <item>Init scripts ending in .sh are not handled specially.  They are not
  sourced and are not guaranteed to be run by <prgn>/bin/sh</prgn> regardless
  of the #! line.  This brings Policy in line with the long-standing
  behavior of the init system in Debian.
  </item>
<tag>9.3.2</tag>
  <item>The start action of an init script must exit successfully and not
  start the daemon again if it's already running.          
  </item>
<tag>9.3.2</tag>
  <item><file>/var/run</file> and <file>/var/lock</file> may be mounted as
  temporary filesystems, and init scripts must therefore create any necessary
  subdirectories dynamically.                                             
  </item>
<tag>10.4</tag>
  <item> <file>/bin/sh</file> scripts may assume that local can take multiple
   variable arguments and supports assignment.                       
  </item>
<tag>11.6</tag>
  <item>User mailboxes may be mode 600 and owned by the user rather than
  mode 660, owned by user, and group mail.                 
  </item>
</taglist></p>

<sect> Version 3.8.0.0
<p>

Released  Jun 2008.

</p><p><taglist>
<tag>2.4, 3.7</tag>
<item>The base section has been removed.  contrib and non-free have been
  removed from the section list; they are only categories.  The base
  system is now defined by priority.                       
<tag>4.9</tag>
<item>If <prgn>dpkg-source -x</prgn> doesn't provide the source that will be
  compiled, a debian/rules patch target is recommended and should do whatever
  else is necessary.
<tag>4.9.1, 10.1</tag>
<item>Standardized the format of DEB_BUILD_OPTIONS.  Specified permitted
  characters for tags, required that tags be whitespace-separated,
  allowed packages to assume non-conflicting tags, and required
  unknown flags be ignored.                                
<tag>4.9.1</tag>
<item>Added parallel=n to the standardized DEB_BUILD_OPTIONS tags,
  indicating that a package should be built using up to n parallel
  processes if the package supports it                     
<tag>4.13</tag>
<item>Debian packages should not use convenience copies of code from other
  packages unless the included package is explicitly intended to be
  used that way.                                           
<tag>4.14</tag>
<item>If dpkg-source -x doesn't produce source ready for editing and
  building with dpkg-buildpackage, packages should include a
  <file>debian/README.source</file> file explaining how to generate
  the patched source, add a new modification, and remove an existing
  modification.  This file may also be used to document packaging a
  new upstream release and any other complexity of the Debian build
  process.                                                 
<tag>5.6.3</tag>
<item>The Uploaders field in debian/control may be wrapped.    
<tag>5.6.12</tag>
<item>An empty Debian revision is equivalent to a Debian revision of 0 in
  a version number.                                        
<tag>5.6.23</tag>
<item>New Homepage field for upstream web sites.               
<tag>6.5, 6.6, 7</tag>
<item>The Breaks field declares that this package breaks another and
  prevents installation of the breaking package unless the package
  named in Breaks is deconfigured first.  This field should not be
  used until the dpkg in Debian stable supports it.        
<tag>8.1, 8.2</tag>
<item>Clarify which files should go into a shared library package, into a
  separate package, or into the -dev package.  Suggest -tools instead
  of -runtime for runtime support programs, since that naming is more
  common in Debian.                                        
<tag>9.5</tag>
<item>Files in <file>/etc/cron.{hourly,daily,weekly,monthly}</file> must be
  configuration files (upgraded from should).  Mention the hourly
  directory.                                               
<tag>11.8.6</tag>
<item>Packages providing <file>/etc/X11/Xresources</file> files need not
  conflict with  <tt> xbase (&lt;&lt; 3.3.2.3a-2)</tt>, which is
  long-obsolete.           
<tag>12.1</tag>
<item>Manual pages in locale-specific directories should use either the
  legacy encoding for that directory or UTF-8.  Country names should
  not be included in locale-specific manual page directories unless
  indicating a significant difference in the language.  All
  characters in the manual page source should be representable in the
  legacy encoding for a locale even if the man page is encoded in
  UTF-8.                                                   
<tag>12.5</tag>
<item>The Apache 2.0 license is now in common-licenses and should be
  referenced rather than quoted in <file>debian/copyright</file>.
<tag>12.5</tag>
<item>Packages in contrib and non-free should state in the copyright file
  that the package is not part of Debian GNU/Linux and briefly
  explain why.                                             
<tag>debconf</tag>
<item>Underscore (_) is allowed in debconf template names.     
</taglist></p>

<sect> Version 3.7.3.0
<p>

Released  Dec 2007.

</p><p><taglist>
<tag>5.6.12</tag>
<item>Package version numbers may contain tildes, which sort before
  anything, even the end of a part.                        
<tag>10.4</tag>
<item>Scripts may assume that <file>/bin/sh</file> supports local (at a basic
  level) and that its test builtin (if any) supports -a and -o binary
  logical operators.                                       
<tag>8.5</tag>
<item>The substitution variable ${binary:Version} should be used in place
  of ${Source-Version} for dependencies between packages of the same
  library.                                                 
<tag>menu policy</tag>
<item>Substantial reorganization and renaming of sections in the Debian
  menu structure.  Packages with menu entries should be reviewed to
  see if the menu section has been renamed or if one of the new
  sections would be more appropriate.                      
<tag>5.6.1</tag>
<item>The Source field in a .changes file may contain a version number
  in parentheses.                                          
<tag>5.6.17</tag>
<item>The acceptable values for the Urgency field are low, medium, high,
  critical, or emergency.                                  
<tag>8.6</tag>
<item>The shlibs file now allows an optional type field, indicating the
  type of package for which the line is valid.  The only currently
  supported type is udeb, used with packages for the Debian
  Installer.                                               
<tag>3.9.1</tag>
<item>Packages following the Debian Configuration management
  specification must allow for translation of their messages by using
  a gettext-based system such as po-debconf.               
<tag>12.5</tag>
<item>GFDL 1.2, GPL 3, and LGPL 3 are now in common-licenses and should
  be referenced rather than quoted in debian/copyright.
</taglist></p>

<sect> Version 3.7.2.2
<p>

Released  Oct 2006.

</p><p><taglist>
<tag>6.1</tag> <item>Maintainer scripts must not be world writeable (up from a
    should to a must)</item>   
</taglist></p>

<sect> Version 3.7.2.0
<p>

Released  Apr 2006.

</p><p><taglist>
<tag>11.5</tag> <item>Revert the cgi-lib change. </item>
</taglist></p>

<sect> Version 3.7.1.0
<p>

Released  Apr 2006.

</p><p><taglist>
<tag>10.2</tag>
<item>It is now possible to create shared libraries without
  relocatable code (using -fPIC) in certain exceptional cases,
  provided some procedures are followed, and for creating static
  libraries with relocatable code (again, using -fPIC).
  Discussion on debian-devel@lists.debian.org, getting a rough
  consensus, and documenting it in README.Debian constitute most
  of the process.                                          
<tag>11.8.7</tag>
<item>Packages should install any relevant files into the directories
  <file>/usr/include/X11/</file> and <file>/usr/lib/X11/</file>, but if
  they do so, they must pre-depend on <tt>x11-common (&gt;= 1:7.0.0)</tt>
</taglist></p>

<sect> Version 3.7.0.0
<p>

Released  Apr 2006.

</p><p><taglist>
<tag>11.5</tag>
<item>Packages shipping web server CGI files are expected to install
  them in <file>/usr/lib/cgi-lib/</file> directories.  This location change
  perhaps should be documented in NEWS                     
<tag>11.5</tag>
<item>Web server packages should include a standard scriptAlias of
  cgi-lib to <file>/usr/lib/cgi-lib</file>.
<tag>9.1.1</tag>
<item>The version of FHS mandated by policy has been upped to
  2.3. There should be no changes required for most packages,
  though new top level directories <file>/media</file>, <file>/srv</file>,
  etc.  may be of interest.
<tag>5.1, 5.6.3</tag>
<item>All fields, apart from the Uploaders field, in the control file
  are supposed to be a single logical line, which may be spread
  over multiple physical  lines (newline followed by space is
  elided).  However, any parser for the control file must allow
  the Uploaders field to be spread over multiple physical lines
  as well, to prepare for future changes.
<tag>10.4</tag>
<item>When scripts are installed into a directory in the system
  PATH, the script name should not include an extension that
  denotes the scripting language currently used to implement it.

<tag>9.3.3.2</tag>
<item>packages that invoke initscripts now must use invoke-rc.d to do
  so since it also pays attention to run levels and other local
  constraints.
<tag>11.8.5.2, 11.8.7, etc</tag>
<item>We no longer use <file>/usr/X11R6</file>, since we have
  migrated away to using Xorg paths. This means, for one thing, fonts
  live in <file>/usr/share/fonts/X11/</file> now, and <file>/usr/X11R6</file>
  is gone.
</taglist></p>

<sect> Version 3.6.2.0
<p>

Released  2005

</p><p><taglist>
<tag></tag>
<item>Recommend. doc-base, and not menu, for registering package documentation.
</item>
<tag>8.1</tag>
<item>Run time support programs should live in subdirectories of
  <file>/usr/lib/</file> or <file>/usr/share</file>, and preferably the shared
  lib is named the same as the package name (to avoid name collisions).
</item>
<tag>11.5</tag>
<item>It is recommended that HTTP servers provide an alias /images to
  allow packages to share image files with the web server
</item>
</taglist></p>

<sect> Version 3.6.1.0
<p>

Released  Aug 2003.

</p><p><taglist>
<tag>3.10.1</tag>
<item>Prompting the user should be done using debconf. Non debconf
  user prompts are now deprecated.
</taglist></p>

<sect> Version 3.6.0
<p>

Released  Jul 2003.

</p><p><taglist>
<tag></tag>
<item>Restructuring causing shifts in section numbers and bumping of
  the minor version number:
<tag></tag>
<item>Many packaging manual appendices that were integrated into policy
  sections are now empty, and replaced with links to the Policy.
  In particular, the appendices that included the list of control
  fields were updated (new fields like Closes, Changed-By were added)
  and the list of fields for each of control, .changes and .dsc files
  is now in Policy, and they're marked mandatory, recommended or
  optional based on the current practice and the behavior of the
  deb-building tool-chain.
<tag></tag>
<item>Elimination of needlessly deep section levels, primarily in the
  chapter Debian Archive, from which two new chapters were split out,
  Binary packages and Source packages. What remained was reordered
  properly, that is, some sects became sects etc.
<tag></tag>
<item>Several sections that were redundant, crufty or simply not designed
  with any sort of vision, were rearranged according to the formula that
  everything should be either in the same place or properly interlinked.
  Some things remained split up between different chapters when they
  talked about different aspects of files: their content, their syntax,
  and their placement in the file system. In particular, see the new
  sections about changelog files.
<tag>menu policy</tag>
<item>Added Games/Simulation and Apps/Education to menu
  sub-policy
<tag>C.2.2</tag>
<item>Debian changelogs should be UTF-8 encoded.
<tag>10.2</tag>
<item>shared libraries must be linked against all libraries that they
  use symbols from in the same way that binaries are.
<tag>7.6</tag>
<item>build-depends-indep need not be satisfied during clean
  target.
</taglist></p>

<sect> Version 3.5.10
<p>

Released  May 2003.

</p><p><taglist>
<tag>11.8.3</tag>
<item>packages providing the x-terminal-emulator virtual package
  ought to ensure that they interpret the command line exactly
  like xterm does.
<tag>11.8.4</tag>
<item>Window managers compliant with the Window Manager Specification
  Project may add 40 points for ranking in the alternatives
</taglist></p>

<sect> Version 3.5.9.0
<p>

Released  Mar 2003.

</p><p><taglist>
<tag>3.4.2</tag>
<item>The section describing the Description: package field once again has
  full details of the long description format.
<tag>4.2</tag>
<item>Clarified that if a package has non-build-essential
  build-dependencies, it should have them listed in the Build-Depends
  and related fields (i.e. it's not merely optional).
<tag>9.3.2</tag>
<item>When asked to restart a service that isn't already running,
  the init script should start the service.
<tag>12.6</tag>
<item>If the purpose of a package is to provide examples, then the
  example files can be installed into <file>/usr/share/doc/package</file>
  (rather than <file>/usr/share/doc/package/examples</file>).
</taglist></p>

<sect> Version 3.5.8.0
<p>

Released  Nov 2002.

</p><p><taglist>
<tag>12.7</tag>
<item>It is no longer necessary to keep a log of changes to the upstream
  sources in the copyright file. Instead, all such changes should be
  documented in the changelog file.
<tag>7.6</tag>
<item><var/Build-Depends/, <var/Build-Conflicts/, <var/Build-Depends-Indep/,
  and <var/Build-Conflicts-Indep/ must also be satisfied when the clean
  target is called.
<tag>menu policy</tag>
<item>A new Apps/Science menu section is available
<tag>debconf policy</tag>
<item>debconf specification cleared up, various changes.
<tag>12.1</tag>
<item>It is no longer recommended to create symlinks from nonexistent
  manual pages to undocumented(7). Missing manual pages for programs
  are still a bug.
</taglist></p>

<sect> Version 3.5.7.0
<p>

Released  Aug 2002.

</p><p><taglist>
<tag></tag>
<item>Packages no longer have to ask permission to call MAKEDEV in
  postinst, merely notifying the user ought to be enough.
<tag>2.2.4</tag>
<item>cryptographic software may now be included in the main
  archive.
<tag>3.9</tag>
<item>task packages are no longer permitted; tasks are now created by a
  special Tasks: field in the control file.
<tag>11.8.4</tag>
<item>window managers that support netwm can now add 20 points when
  they add themselves as an alternative for
 <file>/usr/bin/x-window-manager</file>
<tag>10.1</tag>
<item>The default compilation options have now changed, one should
  provide debugging symbols in all cases, and optionally step
  back optimization to -O0, depending on the DEB_BUILD_OPTIONS
  environment variable.
<tag>7.6, 4.8</tag>
<item>Added mention of build-arch, build-indep, etc, in describing
  the relationships with `Build-Depends', `Build-Conflicts',
  `Build-Depends-Indep', and `Build-Conflicts-Indep'. May need to
  review the new rules.
<tag>8</tag>
<item>Changed rules on how, and when, to invoke ldconfig in maintainer
  scripts. Long rationale.
</taglist></p>

<p><em>
Added the last note in 3.5.6 upgrading checklist item regarding build
rules, please see below
</em></p>

<sect> Version 3.5.6.0
<p>

Released  Jul 2001.

</p><p><taglist>
<tag>2.5</tag>
<item>Emacs and TeX are no longer mandated by policy to be priority
  standard packages
<tag>11.5</tag>
<item>Programs that access docs need to do so via <file>/usr/share/doc</file>,
  and not via <file>/usr/doc/</file> as was the policy previously
<tag>12.3</tag>
<item>Putting documentation in <file>/usr/doc</file> versus
 <file>/usr/share/doc</file> is now a ``serious'' policy violation.
<tag>11.5</tag>
<item>For web servers, one should not provide non-local access to the
  <file>/usr/share/doc</file> hierarchy. If one can't provide access
  controls for the http://localhost/doc/ directory, then it is preferred
  that one ask permission to expose that information during the install.
<tag>7</tag>
<item>There are new rules for build-indep/build-arch targets and
  there is a new Build-Depend-Indep semantic.
</taglist></p>

<sect> Version 3.5.5.0
<p>

Released  May 2001.

</p><p><taglist>
<tag>12.1</tag>
<item>Manpages should not rely on header information to have
  alternative manpage names available; it should only use
  symlinks or .so pages to do this
</item>
<tag></tag>
<item><em> Clarified note in 3.5.3.0 upgrading checklist regarding
   examples and templates: this refers only to those examples used
   by scripts; see section 10.7.3 for the whole story</em>
</item>
<tag></tag>
<item>Included a new section 10.9.1 describing the use of
  dpkg-statoverride; this does not have the weight of policy
</item>
<tag></tag>
<item>Clarify Standards-Version: you don't need to rebuild your
  packages just to change the Standards-Version!
</item>
<tag>10.2</tag>
<item>Plugins are no longer bound by all the rules of shared
  libraries
</item>
<tag>X Windows related things:</tag>
<item><taglist>
  <tag>11.8.1</tag>
  <item>Clarification of priority levels of X Window System related
      packages
  </item>
  <tag>11.8.3</tag>
  <item>Rules for defining x-terminal-emulator improved </item>
  <tag>11.8.5</tag>
  <item>X Font policy rewritten: you must read this if you provide
      fonts for the X Window System
  </item>
  <tag>11.8.6</tag>
  <item>Packages must not ship <file>/usr/X11R6/lib/X11/app-defaults/</file>
  </item>
  <tag>11.8.7</tag>
  <item>X-related packages should usually use the regular FHS
      locations; imake-using packages are exempted from this
  </item>
  <tag>11.8.8</tag>
  <item>OpenMotif linked binaries have the same rules as
      OSF/Motif-linked ones
  </item>
  </taglist></item>
</taglist></p>

<sect> Version 3.5.4.0
<p> Released  Apr 2001.

</p><p><taglist>
<tag>11.6</tag>
<item>The system-wide mail directory is now /var/mail, no longer
  /var/spool/mail.  Any packages accessing the mail spool should
  access it via /var/mail and include a suitable Depends field;
  details in
</item>
<tag>11.9; perl-policy</tag>
<item>The perl policy is now part of Debian policy
  proper. Perl programs and modules should follow the current Perl
  policy
</item>
</taglist></p>

<sect> Version 3.5.3.0
<p> Released Apr 2001

</p><p><taglist>
<tag>7.1</tag>
<item>Build-Depends arch syntax has been changed to be less
  ambiguous. This should not affect any current packages
</item>
<tag>10.7.3</tag>
<item>Examples and templates files for use by scripts should now live
  in <file>/usr/share/&lt;package&gt;</file> or
  <file>/usr/lib/&lt;package&gt;</file>, with symbolic links from
  <file>/usr/share/doc/&lt;package&gt;/examples</file> as needed
</item>
</taglist></p>

<sect> Version 3.5.2.0

<p> Released Feb 2001.

</p><p><taglist>
<tag>11.8.6</tag>
<item>X app-defaults directory has moved from
  <file>/usr/X11R6/lib/X11/app-defaults</file> to
  <file>/etc/X11/app-defaults</file>
</item>
</taglist></p>

<sect> Version 3.5.1.0

<p> Released Feb 2001.

</p><p><taglist>
<tag>8.1</tag>
<item>dpkg-shlibdeps now uses objdump, so shared libraries have to be
  run through dpkg-shlibdeps as well as executables
</item>
</taglist></p>

<sect> Version 3.5.0.0

<p> Released Jan 2001.

</p><p><taglist>
<tag>11.8.5</tag>
<item>Font packages for the X Window System must now declare a
  dependency on xutils (>= 4.0.2)
</item>
</taglist></p>

<sect> Version 3.2.1.1

<p> Released Jan 2001.

</p><p><taglist>
<tag>9.3.2</tag>
<item>Daemon startup scripts in <file>/etc/init.d/</file> should not contain
  modifiable parameters; these should be moved to a file in
  <file>/etc/default/</file>
</item>
<tag>12.3</tag>
<item>Files in <file>/usr/share/doc</file> must not be referenced by any
  program.  If such files are needed, they must be placed in
  <file>/usr/share/&lt;package&gt;/</file>, and symbolic links
  created as required in <file>/usr/share/doc/&lt;package&gt;/</file>
</item>
<tag></tag>
<item>Much of the packaging manual has now been imported into the
  policy document
</item>
</taglist></p>

<sect> Version 3.2.1.0

<p> Released Aug 00.

</p><p><taglist>
<tag>11.8.1</tag>
<item>A package of priority standard or higher may provide two
  binaries, one compiled with support for the X Window System,
  and the other without
</item>
</taglist></p>

<sect> Version 3.2.0.0

<p> Released Aug 00.

</p><p><taglist>
<tag>10.1</tag>
<item>By default executables should not be built with the debugging
  option -g. Instead, it is recommended to support building the
  package with debugging information optionally.  Details in
</item>
<tag>12.8</tag>
<item>Policy for packages where the upstream uses HTML changelog
  files has been expanded.  In short, a plain text changelog file
  should always be generated for the upstream changes
</item>
<tag></tag>
<item>Please note that the new release of the X window system (3.2)
  shall probably need sweeping changes in policy
</item>
<tag></tag>
<item>Policy for packages providing the following X-based features
  has been codified:
  <taglist>
  <tag>11.8.2</tag>
  <item>X server (virtual package xserver) </item>
  <tag>11.8.3</tag>
  <item>X terminal emulator (virtual package x-terminal-emulator) </item>
  <tag>11.8.4</tag>
  <item>X window manager (virtual package x-window-manager, and
      <file>/usr/bin/x-window-manager</file> alternative, with priority
      calculation guidelines)
  </item>
  <tag>12.8.5</tag>
  <item>X fonts (this section has been written from scratch) </item>
  <tag>11.8.6</tag>
  <item>X application defaults </item>
  </taglist>
</item>
<tag>11.8.7</tag>
<item>Policy for packages using the X Window System and FHS issues
  has been clarified;
</item>
<tag>11.7.3</tag>
<item>No package may contain or make hard links to conffiles </item>
<tag>8</tag>
<item>Noted that newer dpkg versions do not require extreme care in
  always creating the shared lib before the symlink, so the unpack
  order be correct
</item>
</taglist></p>

<sect> Version 3.1.1.0

<p> Released Nov 1999.

</p><p><taglist>
<tag>7.1</tag>
<item>Correction to semantics of architecture lists in Build-Depends
  etc.  Should not affect many packages
</item>
</taglist></p>

<sect> Version 3.1.0.0

<p> Released Oct 1999.

</p><p><taglist>
<tag>defunct</tag>
<item><file>/usr/doc/&lt;package&gt;</file> has to be a symlink pointing to
  <file>/usr/share/doc/&lt;package&gt;</file>, to be maintained by postinst
  and prerm scripts.
</item>
<tag>7.1, 7.6</tag>
<item>Introduced source dependencies (Build-Depends, etc.) </item>
<tag>9.3.4</tag>
<item><file>/etc/rc.boot</file> has been deprecated in favour of
  <file>/etc/rcS.d</file>.  (Packages should not be touching this directory,
  but should use update-rc.d instead)
</item>
<tag>9.3.3</tag>
<item>update-rc.d is now the <em>only</em> allowable way of accessing the
  <file>/etc/rc?.d/[SK]??*</file> links.  Any scripts which manipulate them
  directly must be changed to use update-rc.d instead.  (This is
  because the file-rc package handles this information in an
  incompatible way.)
</item>
<tag>12.7</tag>
<item>Architecture-specific examples go in
  <file>/usr/lib/&lt;package&gt;/examples</file>
  with symlinks from <file>/usr/share/doc/&lt;package&gt;/examples/*</file>
  or from <file>/usr/share/doc/&lt;package&gt;/examples</file> itself
</item>
<tag>9.1.1</tag>
<item>Updated FHS to a 2.1 draft; this reverts <file>/var/state</file> to
  <file>/var/lib</file>
</item>
<tag>9.7; mime-policy</tag>
<item>Added MIME sub-policy document </item>
<tag>12.4</tag>
<item>VISUAL is allowed as a (higher priority) alternative to EDITOR
</item>
<tag>11.6</tag>
<item>Modified liblockfile description, which affects
  mailbox-accessing programs.  Please see the policy document for
  details
</item>
<tag>12.7</tag>
<item>If a package provides a changelog in HTML format, a text-only
  version should also be included.  (Such a version may be prepared
  using <prgn>lynx -dump -nolist</prgn>.)
</item>
<tag>3.2.1</tag>
<item>Description of how to handle version numbers based on dates
  added
</item>
</taglist></p>

<sect> Version 3.0.1.0

<p> Released Jul 1999.

</p><p><taglist>
<tag>10.2</tag>
<item>Added the clarification that the .la files are essential for
  the packages using libtool's libltdl library, in which case the .la
  files must go in the run-time library package
</item>
</taglist></p>

<sect> Version 3.0.0.0

<p> Released Jun 1999.

</p><p><taglist>
<tag>9.1</tag>
<item>Debian formally moves from the FSSTND to the FHS. This is a
  major change, and the implications of this move are probably
  not all known.
</item>
<tag>4.1</tag>
<item>Only 3 digits of the Standards version need be included in
  control files, though all four digits are still permitted.
</item>
<tag>12.6</tag>
<item>The location of the GPL has changed to
  <file>/usr/share/common-licenses</file>. This may require changing the
  copyright files to point to the correct location of the GPL and
  other major licenses
</item>
<tag>10.2</tag>
<item>Packages that use libtool to create shared libraries must
  include the .la files in the -dev packages
</item>
<tag>10.8</tag>
<item>Use logrotate to rotate log files
</item>
<tag>now 11.8</tag>
<item>section 5.8 has been rewritten (Programs for the X Window
  System)
</item>
<tag>9.6; menu-policy</tag>
<item>There is now an associated menu policy, in a separate document,
  that carries the full weight of Debian policy
</item>
<tag>11.3</tag>
<item>Programs which need to modify the files <file>/var/run/utmp</file>,
  <file>/var/log/wtmp</file> and <file>/var/log/lastlog</file> must be
  installed setgid utmp
</item>
</taglist></p>
<p><em>
   Please note that section numbers below this point may not be up to date
</em></p>

<sect> Version 2.5.0.0

<p> Released Oct 1998.

Policy Manual:
</p><p><list>
<item>Rearranged the manual to create a new Section 4, Files
  <list>
  <item>Section 3.3 ("Files") was moved to Section 4. The Sections
    that  were Section 4 and Section 5 were  moved down to become
    Section 5 and Section 6.
  </item>
  <item>What was Section 5.5 ("Log files") is now a subsection of the
    new Section 4 ("Files"), becoming section 4.8, placed after
    "Configuration files", moving the Section 4.8 ("Permissions
    and owners") to Section 4.9.  All subsections of the old
    Section 5 after 5.5  were moved down to fill in the number
    gap.
  </item>
  </list></item>
<item>Modified the section about changelog files to accommodate
  upstream changelogs which were formatted as HTML. These
  upstream changelog files should now be accessible as
  <file>/usr/doc/package/changelog.html.gz</file>
</item>
<item>Symlinks are permissible to link the real, or upstream,
    changelog name to the Debian mandated name.
</item>
<item>Clarified that HTML documentation should be present in some
  package, though not necessarily the main binary package.
  </item>
<item>Corrected all references to the location of the copyright
  files. The correct location is <file>/usr/doc/package/copyright</file>
  </item>
<item>Ratified the architecture specification strings to cater to the
  HURD.
  </item>
</list></p>

<sect> Version 2.4.1.0

<p> Released Apr 1998.
</p>
<sect1> Policy Manual:
<p><taglist>
<tag>Updated section 3.3.5 Symbolic links:</tag>
  <item>symbolic links within a toplevel directory should be relative,
    symbolic links between toplevel directories should be absolute
    (cf., Policy Weekly Issue#6, topic 2)
  </item>

<tag>Updated section 4.9 Games:</tag>
  <item>manpages for games should be installed in <file>/usr/man/man6</file>
    (cf., Policy Weekly Issue#6, topic 3)
  </item>
</taglist></p>

<sect1> Packaging Manual:
<p><list>
<item>Updated prefix of chapter 12, Shared Libraries:
  ldconfig must be called in the postinst script if the package
  installs shared libraries
  (cf., Policy Weekly Issue #6, fixes:bug#20515)
</item>
</list></p>

<sect> Version 2.4.0.0

<p> Released Jan 1998

</p><p><taglist>
<tag>Updated section 3.3.4 Scripts:</tag>
  <item><list>
  <item>/bin/sh may be any POSIX compatible shell
  <item>scripts including bashisms have to specify <file>/bin/bash</file>
    as interpreter
  <item>scripts which create files in world-writable directories
    (e.g., in <file>/tmp</file>) should use tempfile or mktemp for creating
    the directory
  </list></item>

<tag>Updated section 3.3.5 Symbolic Links:</tag>
  <item>symbolic links referencing compressed files must have the same
    file extension as the referenced file
  </item>

<tag>Updated section 3.3.6 Device files:</tag>
  <item><file>/dev/tty*</file> serial devices should be used instead of
  <file>/dev/cu*</file>
  </item>

<tag>Updated section 3.4.2 Writing the scripts in <file>/etc/init.d</file>:
  <item><list>
  <item>all <file>/etc/init.d</file> scripts have to provide the following
  options: start, stop, restart, force-reload
  <item>the reload option is optional and must never stop and restart
    the service
  </list></item>

<tag>Updated section 3.5 Cron jobs:
  <item>cron jobs that need to be executed more often than daily should
    be installed into <file>/etc/cron.d</file>
  </item>

<tag>Updated section 3.7 Menus:
  <item>removed section about how to register HTML docs to `menu'
    (the corresponding section in 4.4, Web servers and applications,
    has been removed in policy 2.2.0.0 already, so this one was
    obsolete)
  </item>

<tag>New section 3.8 Keyboard configuration:
  <item>details about how the backspace and delete keys should be
    handled
  </item>

<tag>New section 3.9 Environment variables:
  <item>no program must depend on environment variables to get a
    reasonable default configuration
  </item>

<tag>New section 4.6 News system configuration:
  <item><file>/etc/news/organization</file> and <file>/etc/news/server</file>
    should be supported by all news servers and clients
  </item>

<tag>Updated section 4.7 Programs for the X Window System:
  <item><list>
  <item>programs requiring a non-free Motif library should be provided
    as foo-smotif and foo-dmotif package
  </item>
  <item>if lesstif works reliably for such program, it should be linked
    against lesstif and not against a non-free Motif library
  </item>
  </list></item>

<tag>Updated section 4.9 Games:
  <item>games for X Windows have to be installed in <file>/usr/games</file>,
  just as non-X games
  </item>
</taglist></p>

<sect> Version 2.3.0.1, 2.3.0.0

<p> Released Sep 1997.

<p><list>
<item>new section `4.2 Daemons' including rules for
  <file>/etc/services</file>, <file>/etc/protocols</file>,
  <file>/etc/rpc</file>, and <file>/etc/inetd.conf</file>
</item>

<item>updated section about `Configuration files':
  packages may not touch other packages' configuration files
</item>

<item>MUAs and MTAs have to use liblockfile</item>
</list></p>

<sect> Version 2.2.0.0

<p> Released July 1997.

<p><list>
<item>added section 4.1 `Architecture specification strings':
  use
       &lt;arch&gt;-linux
  where &lt;arch&gt; is one of the following:
       i386, alpha, arm, m68k, powerpc, sparc.
</item>

<item>detailed rules for <file>/usr/local</file></item>

<item>user ID's</item>

<item>editor/pager policy</item>

<item>cron jobs</item>

<item>device files</item>

<item>don't install shared libraries as executable</item>

<item>app-defaults files may not be conffiles</item>
</list></p>

<sect> Version 2.1.3.2, 2.1.3.1, 2.1.3.0

<p> Released Mar 1997.

<p><list>
<item>two programs with different functionality must not have the
  same name </item>

<item>"Webstandard 3.0"</item>

<item>"Standard for Console Messages"</item>

<item>Libraries should be compiled with `-D_REENTRANT'</item>

<item>Libraries should be stripped with <prgn>strip --strip-unneeded</prgn>
</item>
</list></p>

<sect> Version 2.1.2.2, 2.1.2.1, 2.1.2.0

<p> Released Nov 1996.

<p><list>
<item>Some changes WRT shared libraries
</list></p>

<sect> Version 2.1.1.0

<p> Released Sep 1996.

<p><list>
<item>No hard links in source packages</item>

<item>Do not use <prgn>dpkg-divert</prgn> or <prgn>update-alternatives</prgn>
without consultation </item>

<item>Shared libraries must be installed stripped </item>
</list></p>

<sect> Version 2.1.0.0

<p> Released Aug 1996.

<p><list>
  <item>Upstream changelog must be installed too </item>
</list></p>
</book>
</debiandoc>