What is being said is the 97 means it is a 1998 model fork.
Bombers are stamped with the year before the model year, mainly as they are released a few month before the model years year...
And the Z2 means it is a Z2 level
There are a few variation of the Z2 that year, but nor enough to worry about.
Your is the Z2 Alloy, basically the low leg is of the older 97 style, not the new style used that year.
FluffyChicken, so if one were after a Z fork, which of the 80mm variants would be the one to look for?