Frame A203A?

[motogoro]

Just because I'm curious, what does the description "frame A203A" really designate? 
I have seen a few LMIV frames on EU eBay listed as "A203A".  AI tells me "A203A" refers to "authentic vintage or replacement chassis". 
Who, what, where determined that?  Again, just curious.

[guzzisteve]

Frame replacement, frames are marked. If you buy just a frame in parts as new. There is no model tag, square riveted tag on headstock or bracing.
So, you get a frame with this number stamped on it.  Just a guess, I will bet Joe W knows, or Charlie.
Could be the part number.
Just looked, not PT#, There is #1 & 1A & 1B in parts depending on what is welded on headstock.

Good Luck on answer

[Groover]

Found the seller you mention, seems all their listings are followed by numbers similar to that structure; guessing it's their way to locate inventory, like a location on their shelves, etc. Like warehouse location numbers for pickers.

[Antietam Classic Cycle]

Found the seller you mention, seems all their listings are followed by numbers similar to that structure; guessing it's their way to locate inventory, like a location on their shelves, etc. Like warehouse location numbers for pickers.

This ^^^. I bought a fender from the same seller that had a similar code.