Why not using the naming convention used by peeron and Bricklink which is: SSSS-I where SSSS is the set number and I is an index when several sets have the same number?
Using the release year, specially on 2 digit (TLC may soon have 100 years), can be risky, for example for promotional set.
Using the release year, specially on 2 digit (TLC may soon have 100 years), can be risky, for example for promotional set.