In the text of the thread you guys posted:
In the Naruto RP, you are able to create a biography that spans from having no additional ability outside of the Basics ( and not even all of them ), to having elaborate biographies with multiple abilities on it. In the past, certain combinations were banned while others where allowed. In these updated rules, everything that will be capable will be shown below. Of course, this comes with it's own limitations. To state this simply, Kekkei Genkeis (KG), Hidden Abilities (HA), Advanced Elements (AE), and Custom Clans are now defined as Core Abilities. Core Abilities are able to have up to 2 Skills on a bio, which are Modes and Advanced Ninjutsu. If a member chooses to have a second Core Ability, they will replace one of their 2 Skills. The only current exception is Custom Clan bios which currently cannot have a second Core Ability, though this will change soon as well.
As for Cannon bio, it would be a case by case thing if I'm not mistaken.