+The full form of a footnote command for both Event- and Time-based
+footnotes is
+
+@example
+[@var{direction}] \footnote [@var{mark}] @var{offset} [@var{grob-name}] @var{footnote} @var{music}
+@end example
+
+The elements are:
+
+@table @var
+
+@item direction
+If (and only if) the @code{\footnote} is being applied to a
+post-event or articulation, it must be preceded with a direction
+indicator (@code{-, _, ^}) in order to attach @var{music} (with
+a footnote mark) to the preceding note or rest.
+
+@item mark
+is a markup or string specifying the footnote mark which is used for
+marking both the reference point and the footnote itself at the
+bottom of the page. It may be omitted (or equivalently replaced with
+@code{\default}) in which case a number in sequence will be generated
+automatically. Such numerical sequences restart on each page
+containing a footnote.
+
+@item offset
+is a number pair such as @samp{#(2 . 1)} specifying the X and
+Y@tie{}offsets in units of staff-spaces from the boundary of the
+object where the mark should be placed. Positive values of the
+offsets are taken from the right/top edge, negative values from the
+left/bottom edge and zero implies the mark is centered on the edge.
+
+@item grob-name
+specifies a type of grob to mark (like @samp{#'Flag}). If it is
+given, a grob of that type associated with the referenced @var{music}
+will be used as the reference point. It can be omitted (or replaced
+with @code{\default}) if the footnote mark is to be attached to the
+directly created grob in @var{music}.
+
+@item footnote
+is the markup or string specifying the footnote text to use at the
+bottom of the page.
+
+@item music
+is the music event or chord constituent or post-event that is being
+annotated. While it cannot be omitted, it can be replaced by
+@code{\default} in which case the footnote is not attached to a music
+expression in particular, but rather to a moment of time. It is
+mandatory in this case to use the @var{grob-name} argument for
+selecting an affected grob type, like @samp{#'TimeSignature}.
+
+@end table
+
+@subsubsubheading Event-based footnotes
+
+@cindex footnotes, event-based
+
+The simplest form of event-based footnotes is just
+
+@example
+\footnote @var{offset} @var{footnote} @var{music}
+@end example
+
+This kind of footnote is attached to a layout object directly caused
+by the event corresponding to @var{music}.
+
+@lilypond[quote,verbatim,papersize=a8landscape]