I've added a couple of files to a new subdir of "doc" in gretl CVS,
named "commands".
gretl_commands.dtd is a first stab at a simple DTD for commands. It
will need some extensions (e.g. to allow for structure such as
graphics and equations within the "description" element).
test_command.xml is a trial run, an incomplete account of the ols
command that validates against the DTD.
Allin.