Laser Disk Call #??

[Liberty CU#2 <libc@DARKSTAR.RSA.LIB.IL.US>]

If you use as special call number for your laser disks, what do you use??
LD?
LAS?

We are a small school that just received an influx of disks and in my 8
years experience I don't recall seeing a specific call number.

An example of what I mean, would be a video tape on local history:
VT
977.3
LOC   (title being "Local History")

Would a laser disk be:
LD
977.3
LOC  ???

thanks...    libc@darkstar.rsa.lib.il.us