When deploying, I have been told officers can get an additional clothing allowance. If this is true, what is the form I need to fill out?

For Guard coming on to active duty, at least, it is a bit different. You can get a clothing allowance as long as you haven't received a clothing allowance in the past 2 years (?). it is typically processed through milpay and your S1 should be able to run that down for you.

The Army may be different, but I recall the Navy only authorized an initial post-commissioning clothing allowance for officers...the only exception I believe being within 90 days of re-affiliating, or something like that. Seeing as how I left Annapolis weighing like 120...I had to pretty much buy everything out of pocket at least once or twice over the years. Man-getting sleeve braid on SDBs? That's a wallet buster!

When I deployed to Afghanistan, I was issued so many DCUs, I still have pants kicking around I use for painting, gardening, etc. I imagine if someone was coming into the Reserves after a period of IRR, and there had been major uni changes (like there have been)...there may be exemptions.