I've gotten some different calls over the years. I come up with the specialties as being:
Residential Commercial / master keying Office furniture locks Auto locks / remake keys, or replace locks Auto unlocking Safe and vault service Safe and vault opening Safe deposit box opening Residential unlocking
I've done most of these in some form or other during my career. What other sub specialties are there? I guess Medeco, Abloy, Assa, and other high security.