Originally Posted by Cal Soulshadow

Basically, yes. The guild needs to have been around two months and then is voted in or not based on its interactions with other member guilds.

However, with the disintigration of CoY and ERPA, and more guilds willing to war each other irrespective of affiliation, then membership is not really essential. CoRE membership is more like a guarantee of quality, like the little lions you get stamped on your eggs.