[FFTA2] About an unknown flag in the Ability editor

[DeLec]

Hello! First time here.
I was looking at the unknown flag in the ability editor below the "learnable by blue magick" flag, and by parsing through all the abilities, I found that it is unticked if the ability :
- resurects someone else
- gives the player loot (not items)
- is a skill specific to a boss (Neukhia, Demon Wall, Rafflesia, Yowie, Upsilon, Klesta and Keeper)
- is a suicide move (the user dies)
- gives charm without doing damage (except for Ljda and Cupid)
- KOes without doing damage
- Summon Allies (like Summon Pack or Wake the Dead)
- is a Beastmaster, Mirrored Item, Tomberry, Magick Pot, Esper or placeholder skill
- is one of the following skills (no patterns found) :
Cornered (blue mage)
Matra Magick (blue mage)
Transmute (Alchemist) 
Awareness (Ranger)
Limit Glove (Great Tortoise) the blue mage's Cornered (but not the tortoise's Matra Magick)
Munch (Adamantitan, Toughskin)
Purify (Malboro)
Brute Strength (Headless, Wendigo, Golem)
Helmsplitter (Wendigo, Golem)

Any ideas on what the global theme, coding logic could be ?