IBC == Instant Background Check
CHL == Concealed Handgun License
CHP = Concealed Handgun Permit
There are of course other terms which vary by state or other jurisdiction. If the license/permit process meets certain criteria, mainly requiring a background check, then the holder of such license or permit can buy firearms, from a dealer, without undergoing the "instant" check (anyone can do so from a non-dealer). That's federal law, your situation may be different depending on state laws.