[Wim Lewis]

I think the menu under "Edit > Insert Variable" (IIRC) will show all the variables OmniGraffle has. The variables *should* all be listed in the help as well, especially since some of them can take extra parameters, like a format string for the datestamp variables.

If they're in the help but you had a hard time finding them, could you post what you searched on, etc., which didn't work? Sometimes we forget to add index terms which are obvious in retrospect…