According to Chris Dee, the following already shows up on LEGO Universe parts:
0 !HISTORY YYYY-MM-DD {The LEGO Universe Team} Original part shape
0 !HISTORY YYYY-MM-DD [UserName] File preparation for LDraw Parts Tracker
As far as I know, the above is a de facto standard, though; I don't think the LSC ever required it to be that way. I think both LEGO Universe-derived parts and LDD-derived parts should be treated the same.
0 !HISTORY YYYY-MM-DD {The LEGO Universe Team} Original part shape
0 !HISTORY YYYY-MM-DD [UserName] File preparation for LDraw Parts Tracker
As far as I know, the above is a de facto standard, though; I don't think the LSC ever required it to be that way. I think both LEGO Universe-derived parts and LDD-derived parts should be treated the same.