> I would say it is almost certain that it used to be some > X11-specific hack decades ago that has never been maintained > or tested since, because neither GNU troff nor Heirloom troff > define an .ny or .ny0 request.
In the Xlib documentation, the ".ny0" first appeared in X11R1 (apparently with no explanation), X10R4 did not yet have it. And from looking at the source code, it appears that AT&T troff also never had an _undocumented_ .ny request (unless it was carefully hidden). If it's not a typo that went unrecognized because it didn't do any harm, then perhaps the .ny0 was intended for some other troff (being simply ignored by AT&T troff)? The Makefile runs "psroff", but I thought that was only a wrapper for the regular troff to generate Postscript output. Were any other troffs in widespread use at the time (ca. 1985)?
