Many of us have good reasons to submit their papers to the math archives such as math.OA or math.MP. Please observe that the math archive math.MP is entirely unrelated from the physics archive math-ph, and consequently crosslinks to MP within math are not seen by math-ph users.
It is therefore highly recommendable to put a crosslink to math-ph (or some other physics archive) in order to ensure visibility of your work also in the physics community. You may add a crosslink at any later time (that is, also for your "ancient" papers), e.g., by using the cross-link form at xxx.lanl.gov/uploads, entering the password for your paper, then selecting "physics" in the bottom line and reloading the form.
Last modified: Fri May 17 15:18:55 CEST 2002