+----------------------------+
| 'e' | USE_EXCEPT |
|------+---------------------|
+ | 'g' | NO_FAKE_GLINES |
+ |------+---------------------|
+ | 'G' | GLINES |
+ |------+---------------------|
| 'H' | HUB |
|------+---------------------|
| 'I' | USE_INVEX |