Frame Duration Keyword
F parameter and % switch alternative.
Used as a parameter this keyword sets the default frame duration (in ticks,
one tick being one retrace interval, typically 1/60th of a second or 16.666
milliseconds), when used in a frame this keyword sets the duration of that frame (or more correctly, the time that the next frame is scheduled
which means that if there are no more frames in the item it's duration doesn't
mean anything as there's nothing more left for DMDX to do once that frame is
displayed so DMDX will move onto what comes next).
If you need to specify this in milliseconds please use the
NOTE: This parameter (or
must be specified otherwise the default frame duration will be zero leading to
some distinctly weird behavior (these days there's actually warning if the
default frame duration isn't specified)..