for historical reference.
+----------------------------+
| 'e' | USE_EXCEPT |
|------+---------------------|
+ | 'g' | NO_FAKE_GLINES |
+ |------+---------------------|
+ | 'G' | GLINES |
+ |------+---------------------|
| 'H' | HUB |
|------+---------------------|
| 'I' | USE_INVEX |
EOB - supports end of burst notification (EOB token)
KLN - supports remote KLINE
UNKLN - supports remote UNKLINE
+GLN - supports hybrid7-style GLINE (:oper GLINE user host :reason)
HOPS - supports halfops (+h -- %<nick>)
HUB - denotes that the target server is a HUB
AOPS - supports anonymous ops (+a, op hiding/op status hiding)