The valid race/class combinations are controlled in world by this table in client.cpp
Code:
bool ClassRaceLookupTable[PLAYER_CLASS_COUNT][_TABLE_RACES]=
{ /*Human Barbarian Erudite Woodelf Highelf Darkelf Halfelf Dwarf Troll Ogre Halfling Gnome Iksar Vahshir Froglok*/
{ /*Warrior*/ true, true, false, true, false, true, true, true, true, true, true, true, true, true, true},
{ /*Cleric*/ true, false, true, false, true, true, true, true, false, false, true, true, false, false, true},
{ /*Paladin*/ true, false, true, false, true, false, true, true, false, false, true, true, false, false, true},
{ /*Ranger*/ true, false, false, true, false, false, true, false, false, false, true, false, false, false, false},
{ /*ShadowKnight*/ true, false, true, false, false, true, false, false, true, true, false, true, true, false, false},
{ /*Druid*/ true, false, false, true, false, false, true, false, false, false, true, false, false, false, false},
{ /*Monk*/ true, false, false, false, false, false, false, false, false, false, false, false, true, false, false},
{ /*Bard*/ true, false, false, true, false, false, true, false, false, false, false, false, false, true, false},
{ /*Rogue*/ true, true, false, true, false, true, true, true, false, false, true, true, false, true, false},
{ /*Shaman*/ false, true, false, false, false, false, false, false, true, true, false, false, true, true, true},
{ /*Necromancer*/ true, false, true, false, false, true, false, false, false, false, false, true, true, false, false},
{ /*Wizard*/ true, false, true, false, true, true, false, false, false, false, false, true, false, false, true},
{ /*Magician*/ true, false, true, false, true, true, false, false, false, false, false, true, false, false, false},
{ /*Enchanter*/ true, false, true, false, true, true, false, false, false, false, false, true, false, false, false},
{ /*Beastlord*/ false, true, false, false, false, false, false, false, true, true, false, false, true, true, false },
{ /*Berserker*/ false, true, false, false, false, false, false, true, true, true, false, false, false, true, false }
};//Initial table by kathgar, editted by Wiz for accuracy, solar too
Not sure what "number correlations" you are speaking about.