Be puzzled no more. An ex-Intel employee has given us the lowdown of what the long strings mean, and here's his guide through the mobo thicket:
"The D 845GL LY (D845GLLY) means this. D is for Desktop. This means the board is positioned toward the desktop PC market. Intel also uses S for Server, and W for Workstation.
"Some boards will have chipset names that are just the three numbers, some will have added letters such as E, G, GL, EP, etc... If the board uses a non-Intel chipset - right now, only their server boards do -- then there is no chipset identifier, such as the SBT2.
"LY is the board's name. The last two letters are the name of the board. Intel names their boards after North American cities (SE440BX =Seattle, MO810/D810EMO = Montreal, D850GB = Granite Bay) although I don't know what any of the current codenames are.
"Sometimes there will be a number at the end, such as the SBT2 or D850EMV2. This either indicates a second revision of that board (in desktop boards, like the tried-and-true Seattle series) or it indicates the number of processors (in server and workstation boards.)
"So, we've got the D845GLLY. It's a desktop board, it's codename is LY, and it uses the 845GL chipset. Let's assume for a moment that Intel comes out with an 845GLL chipset. Let's further assume that this board gets named 'London'. This board would end up with the name D845GLLLO. Now we've got three Ls in a row."
We hope that helps when you're trying to sort out the sheep from the lambs. µ