| Good | Not So Good | |------|--------------| | Works well for 1977–present Gibson USA | Older (pre-1977) numbers are inconsistent | | Useful for verifying year | Can’t always detect fakes—forged serials exist | | Free & fast (official Gibson decoder) | Some custom shop reissues show “wrong” year by design | | Batch numbers help match period-correct specs | Not all Epiphone numbers decode reliably |