+@seealso
+
+For modern clefs, see @ref{Clef}. For the percussion clef, see
+@ref{Percussion staves}. For the @code{TAB} clef, see
+@ref{Tablatures}.
+
+
+@node Ancient flags
+@subsection Ancient flags
+
+@cindex flags
+
+@syntax
+
+Use the @code{flag-style} property of grob @internalsref{Stem} to
+select ancient flags. Besides the @code{default} flag style,
+currently only @code{mensural} style is supported:
+
+@lilypond[fragment,singleline,verbatim]
+ \property Voice.Stem \set #'flag-style = #'mensural
+ \property Voice.Stem \set #'thickness = #1.0
+ \property Voice.NoteHead \set #'style = #'mensural
+ \autoBeamOff
+ c'8 d'8 e'8 f'8 c'16 d'16 e'16 f'16 c'32 d'32 e'32 f'32 s8
+ c''8 d''8 e''8 f''8 c''16 d''16 e''16 f''16 c''32 d''32 e''32 f''32
+@end lilypond
+
+Note that the innermost flare of each mensural flag always is
+vertically aligned with a staff line. If you do not like this
+behaviour, you can set the @code{adjust-if-on-staffline} property of
+grob @internalsref{Stem} to @code{##f}. Then, the vertical position
+of the end of each flare is different between notes on staff lines and
+notes between staff lines:
+
+@lilypond[fragment,singleline]
+ \property Voice.Stem \set #'flag-style = #'mensural
+ \property Voice.Stem \set #'thickness = #1.0
+ \property Voice.Stem \set #'adjust-if-on-staffline = ##f
+ \property Voice.NoteHead \set #'style = #'mensural
+ \autoBeamOff
+ c'8 d'8 e'8 f'8 c'16 d'16 e'16 f'16 c'32 d'32 e'32 f'32 s8
+ c''8 d''8 e''8 f''8 c''16 d''16 e''16 f''16 c''32 d''32 e''32 f''32
+@end lilypond
+
+There is no particular flag style for neo-mensural notation. Hence,
+when typesetting e.g. the incipit of a transcibed piece of mensural
+music, the default flag style should be used. There are no flags in
+Gregorian Chant notation.
+
+
+@node Ancient time signatures
+@subsection Ancient time signatures
+
+@cindex time signatures
+
+@syntax
+
+There is limited support for mensural time signatures. Currently, the
+glyphs are hard-wired to particular time fractions. In other words,
+to get a particular mensural signature glyph with the @code{\time n/m}
+command, @code{n} and @code{m} have to be chosen according to the
+following table:
+
+@lilypond
+\score {
+ \notes {
+ \property Score.timing = ##f
+ \property Score.barAlways = ##t
+ s_\markup { "$\\backslash$time 4/4" }
+ ^\markup { " " \musicglyph #"timesig-neo\_mensural4/4" }
+ s
+ s_\markup { "$\\backslash$time 2/2" }
+ ^\markup { " " \musicglyph #"timesig-neo\_mensural2/2" }
+ s
+ s_\markup { "$\\backslash$time 6/4" }
+ ^\markup { " " \musicglyph #"timesig-neo\_mensural6/4" }
+ s
+ s_\markup { "$\\backslash$time 6/8" }
+ ^\markup { " " \musicglyph #"timesig-neo\_mensural6/8" }
+ \break
+ s_\markup { "$\\backslash$time 3/2" }
+ ^\markup { " " \musicglyph #"timesig-neo\_mensural3/2" }
+ s
+ s_\markup { "$\\backslash$time 3/4" }
+ ^\markup { " " \musicglyph #"timesig-neo\_mensural3/4" }
+ s
+ s_\markup { "$\\backslash$time 9/4" }
+ ^\markup { " " \musicglyph #"timesig-neo\_mensural9/4" }
+ s
+ s_\markup { "$\\backslash$time 9/8" }
+ ^\markup { " " \musicglyph #"timesig-neo\_mensural9/8" }
+ \break
+ s_\markup { "$\\backslash$time 4/8" }
+ ^\markup { " " \musicglyph #"timesig-neo\_mensural4/8" }
+ s
+ s_\markup { "$\\backslash$time 2/4" }
+ ^\markup { " " \musicglyph #"timesig-neo\_mensural2/4" }
+ \break
+ }
+ \paper {
+ indent = 0.0
+ raggedright = ##t
+ \translator {
+ \StaffContext
+ \remove Staff_symbol_engraver
+ \remove Clef_engraver
+ \remove Time_signature_engraver
+ }
+ }
+}
+@end lilypond
+
+Use the @code{style} property of grob @internalsref{TimeSignature} to
+select ancient time signatures. Currently supported styles are
+@code{neo_mensural} and @code{mensural}. The above table uses the
+@code{neo_mensural} style. This style is appropriate e.g. for the
+incipit of transcriptions of mensural pieces. The @code{mensural}
+style mimicks the look of historical printings of the 16th century.
+
+@inputfileref{input/test,time.ly} gives an overview over all available
+ancient and modern styles.
+
+@seealso
+
+@ref{Time signature} gives a general introduction into the use of time
+signatures.
+
+@refbugs
+
+Mensural signature glyphs are currently mapped to time fractions in a
+hard-wired way. This mapping is sensible, but still arbitrary: given
+a mensural time signature, the time fraction represents a modern meter
+that usually will be a good choice when transcribing a mensural piece
+of music. For a particular piece of mensural music, however, the
+mapping may be unsatisfactory. In particular, the mapping assumes a
+fixed transcription of durations (e.g. brevis = half note in 2/2,
+i.e. 4:1). Some glyphs (such as the alternate glyph for 6/8 meter)
+are currently not at all accessible through the @code{\time} command.
+
+Mensural time signatures are supported typographically, but not yet
+musically. The internal representation of durations is currently
+based on a purely binary system; a ternary division such as 1 brevis =
+3 semibrevis (tempus perfectum) or 1 semibrevis = 3 minima (cum
+prolatione maiori) is not correctly handled: event times in ternary
+modes will be badly computed, resulting e.g. in horizontally
+misaligned note heads, and bar checks are likely to erroneously fail.
+
+The syntax and semantics of the @code{\time} command for mensural
+music is subject to change.