Question about FC rep

[Niwashi]

But besides FC credits and rank (which are independent of GC), there's also the reputation level which the FC has with its associated GC. I've never really understood what contributes to that. If it were based on the same credits that Rank is based on, it doesn't seem like it would differ from rank enough to have another measurement of it.

I have, however, seen my FC's reputation with the Flames gradually go higher (currently Honored) even though the only member whose own GC is the same as the FC's GC is a rarely played alt. It must be getting some boost for stuff my main character is doing, who is a member of a different GC (Adders), but I don't know whether an active member in the Flames could boost it faster or not.

The FC's affiliation only determines which Grand Company your officers go to in order to spend credits and buy actions.

And effects how many credits those actions cost. The higher your FC's reputation, the cheaper actions become. I think teleport costs in the region are also affected.