For example, i remember ACN, BCN, DCN, FCN, GCN, HCN, ICN, LCN, PCN, RCN, TCN and UCN, and i took 8 years off. Unknown also merged with TCN at one point and formed a non-fingolfin UCN (unknown council of nations & united council of nations), so I'm pretty sure that's been recycled.

Lol