ABN Aluminum-Brass-Nickel
These are nickel plated instead of chrome, a cheaper process which is not as hard. OS & Thunder Tiger use nickel plating. Nickel wears off much, much faster than chrome.

ABC
From some companies this can mean Aluminum-Brass-Composite. This means they are nickel plated instead of chrome, but are trying to hide it.

AAC Aluminum-Aluminum-Chrome
Chrome plated aluminum cylinder with aluminum piston. Enya uses this sometimes. Some of the Performance Specialties aftermarket racing piston-sleeve sets are AAC.

ABCD
Super Tigre used this configuration once. It had an ABC set up, but the piston also had a Dykes ring (a type of piston ring that I won't go into here)

ASP is an engine brand.