This is a jersey update pack for the New York Knicks.
The jersey filenames are defined like this:
ax,ay,y: Christmas, other uniforms
r1: retro1 (r2-retro2 etc)
r1a: retro1 away (r2a-retro2 away etc)
r1h: retro1 home (r2h-retro2 home etc)
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 the Knicks' black jersey as home, rename to uh014.iff (u-"uniform", h-home, 014-is the team number for Knicks).