Üdvözlünk a GTA5-Mods.com-on

Hi, maybe someone can help me understand.
If my ydd file is .r , the ytd file has to be .whi or .uni ?? What does .u / .r / .whi / .uni stand for?

I`m trying to add addon clothing to a server, and my lowr files are named like this:
ydd file .r
ytd file .whi
BUT, there are some "lowr" that do not work.
What is the problem here?
mp_f_freemode_01_mp_f_customclothes^lowr_003_r.ydd
mp_f_freemode_01_mp_f_customclothes^lowr_diff_003_a_whi.ytd

is this available for mp female too?