Unfortunately the documentation for STDWIN is in a sorry state.
There is nothing here that even remotely resembles a user manual;
"paper.ms" comes closest to a full description.

ABOUT		the old STDWIN blurb that I used to mail out
paper.ms	the original STDWIN report
seldoc.ms	describes using X11 Selections and Cut Buffers in STDWIN
macros.ms	macrose used by seldoc.ms
vtrmdoc.ms	describes the VTRM package used by ../Ports/alfa
man/		manpages for dpv, packages and X11 stdwin

--Guido
