Merge branch 'master' into bug504880-rra

Conflicts:
	policy.sgml

diff --cc policy.sgml
index 8c51a61382f30862c99b409f946290271c3607ea,d4897389639e4d9b0dc19a9b2e33dc9850270bcd..57ff06779bf5b2f2bc484bfa72beef062ecfe5ec
--- 1/policy.sgml
--- 2/policy.sgml
+++ b/policy.sgml
@@@ -4671,22 -4674,25 +4684,25 @@@ Build-Depends: foo [linux-any], bar [an
        <p>
            When one binary package declares a conflict with another
          using a <tt>Conflicts</tt> field, <prgn>dpkg</prgn> will
 -        refuse to allow them to be installed on the system at the
 +        refuse to allow them to be unpacked on the system at the
-         same time.
+         same time.  This is a stronger restriction than <tt>Breaks</tt>,
+         which just prevents both packages from being configured at the
+         same time.  Conflicting packages cannot be unpacked on the
+         system at the same time.
        </p>
  
        <p>
 -        If one package is to be installed, the other must be removed
 -        first.  If the package being installed is marked as replacing
 +        If one package is to be unpacked, the other must be removed
-         first - if the package being unpacked is marked as
-         replacing (see <ref id="replaces">) the one on the system,
-         or the one on the system is marked as deselected, or both
-         packages are marked <tt>Essential</tt>, then
-         <prgn>dpkg</prgn> will automatically remove the package
-         which is causing the conflict, otherwise it will halt the
-         installation of the new package with an error.  This
-         mechanism is specifically designed to produce an error when
-         the installed package is <tt>Essential</tt>, but the new
-         package is not.
++        first.  If the package being unpacked is marked as replacing
+         (see <ref id="replaces">, but note that <tt>Breaks</tt> should
+         normally be used in this case) the one on the system, or the one
+         on the system is marked as deselected, or both packages are
+         marked <tt>Essential</tt>, then <prgn>dpkg</prgn> will
+         automatically remove the package which is causing the conflict.
+         Otherwise, it will halt the installation of the new package with
+         an error.  This mechanism is specifically designed to produce an
+         error when the installed package is <tt>Essential</tt>, but the
+         new package is not.
        </p>
  
        <p>
@@@ -4885,8 -4956,9 +4966,9 @@@ Provides: mail-transport-agen
  Conflicts: mail-transport-agent
  Replaces: mail-transport-agent
            </example>
 -          ensuring that only one MTA can be installed at any one
 +          ensuring that only one MTA can be unpacked at any one
-           time.
+           time.  See <ref id="virtual"> for more information about this
+           example.
        </sect1>
        </sect>