What does Combat Study do?

in Etrian Odyssey 3 there is a common skill called Combat Study which reads

Listen to the stories of veteras to gain their valuable experiance
EXP Gain ^

Now i took the description as more how it works, that the party is listening to veteran's experiances to gain bonus EXP, sorta like how the Monk's Healing skill says that the Monk uses Qi to heal (but we're using TP to use the skill)

However while looking up on GameFAQs, i came across this section on Miscellaneous Game Tips where it says

• Combat Study
  "Combat Study" is a common skill that allows idle guild members to receive a portion of the exp gained by your main party while in the labyrinth.

which got me confused because i would not have read "EXP Gain ^" as being gaining EXP while NOT in the party, and i already spent 2 points on it for my main party.

I am looking for confirmation as to what does Combat Study do? (to determine if i'm going to sacrifice 5 levels to undo my mistake and spend some time making a bunch of characters for the bench)