that's the dilemma.
on all my other Ibanezes, the color code stamp is exactly in line with the model stamp, same color, same font etc., in a few words: they're both in the same stamp.
same thing for this S, 540S-IH is one stamp.
the stamp issue got me confused for a long time back when i was a kid, and while looking for my first Ibanez' model name, i pulled the neck and discovered the stamp NRG-410BK, and since i was completely ignorant about Ibanez, i was convinced i had an NRG model... then i realized that the N had to be intended separately from the rest. i also realized that BK is for black, while the guitar is pearl white, hehe...