Game Mechanics: Casting beneficial spells on groupmates

[Mafakka]

On Red99:

You can not cast beneficial spells on group mates unless in a duel.

[Smedy]

What spell exactly? I did get buffed by my groupies many times on red99 without any issues.

Were the group mates out of range (pvp range)?

[jilena]

I have buffed people in and out of group with no issues on my shaman and have received cleric and druid buffs on multiple occasions.

[Rogean]

Someone turned in their pvp book like an idiot.