Question about my 540r

[GavinWA]

Hello all!
I am a relatively new guitarist, and have a guitar that up until 20 minutes ago I was telling people was a USAC (thats what it said on the pickup, and I am a newbie).
Thanks to some web research, I found out what I have is a 540r from 1989. Though, I noticed my serial number on the plate has no letter in it, it is only numbers. I thought I read somewhere that these guitars had serial numbers that started with an F. Does this mean anything that mine doesn't? Is this just another beginners observation?
Thanks.

[AlaskaBat]

Look on the back of the headstock.
It could also be a replacement neckplate.

[jer3d]

An 80's Ibanez! Had a couple those myself. Awesome!

http://ibanez.wikia.com/wiki/540R

[Fastmerc]

The late 80's 540's were all assembled in the US and if the serial number is on the neck plate, with the Bensalem or California plate it will not have a letter. The parts were shipped over from Japan and put together in the states. Many people have changed necks, plate, etc so it is not always a positive indication, but if you have a 540r (radius) it should have the USA neckplate.