Yup, Faceman's right; just treat that info as an extra bit of interesting trivia, but the game itself isn't doing anything with those racial divisions. Perhaps they had the intention to implement them all in the game when they wrote that bit of information and they just didn't get around to it; or they just had to find an excuse why one of the NPC's, Viconia, wasn't specified as a "Drow" but merely as the more general "elf".
Apart from the already mentioned Icewind Dale II, I think there are a few BG2-mods which allow you to play more specific elf races (Darkest Day for example, IIRC).
[ 06-16-2003, 11:35 AM: Message edited by: Grojlach ]