This is a jersey update pack for the Boston Celtics.
The jersey filenames are defined like this:
ax,ay,y: Christmas, other uniforms
r1: retro1 (r2-retro2.....)
r1a: retro1 away (r2a-retro2 away.....)
r1h: retro1 home (r2h-retro2 home.....)
ua1: practice away
uh1: practice home
So if you want to use a jersey just rename and copy in the 2K13 folder eg: If you want to use Boston black jersey as home, rename to uh005.iff (u-"uniform", h-home, 005-is the team number for Boston).