Do you ask for a tax receipt (if that's what it's called) so you can use it when filing your taxes?
Do you think it's alright to donate underwear or socks?
I go through my closet every 6 months and if I haven't touched something or worn it, I put it in a bag to donate. I never ask for a receipt for my taxes but I just arranged for The Salvation Army to pick up a dresser, 5 bags of clothes, 1 bag of shoes, 2 bags of linens, 7 pillows, my old wheelchair, a walker, and my kitchenware. I actually asked for a receipt this time.
Sometimes I think I do this not to be nice but just because I want to get rid of all my crap. I hate clutter.
By the way, donating underwear is gross.