Free form PSDS *PROC

When I'm converting my program status data structure from fixed format to
free form, I expect this to work, but it doesn't. Is there a syntax issue,
or do I just have to specify the position for these keywords?

dcl-ds PSDS;
Pgm char(10) *PROC;
RNF3308: Keyword name is not valid; the keyword is ignored.
WSID char(10) pos(244);
User char(10) pos(254);
end-ds;



Work-around is:

dcl-ds PSDS;
Pgm char(10) pos(1);
WSID char(10) pos(244);
User char(10) pos(254);
end-ds;