Vanity for pvp

[Raldo]

Because identifying the enemy BLM/WHM/Whatever is easier when everyone on the entire team isn't wearing the same vanity gear.

While I do technically agree with this, as things currently stand, it literally says the job above their head now, so I could go either way really.

[Nayto]

While I do technically agree with this, as things currently stand, it literally says the job above their head now, so I could go either way really.

Faster target acquisition if the gear is correct.
Especially in frontlines where a wall of nametags pretty much block what your looking for... If I see evenstar/highallag/stupidswanlookingthing then I know it's the damn healer without reading the nametag that requires a magnifying glass (at a long distance).

[ShinigamiZero]

Can be as simple as how other games like League of Legends does it. Purple text, Blue text. Things like that.

[saeedaisspecial]

You missed the point entirely, it's already known each team is going to have different name colors based on their GC.
The point I made was if everyone was in vanity, how do you tell Maelstrom BLM1 to Maelstrom BLM2? They could easily wear the same vanity to confuse the opposing team.
Then you gave the idea that "Oh well they could all have different names like in LoL/Dota!" Where EVERY member of each team has a unique color, do you expect them to have 72 unique colors for identification? Of course not.

Take a look at all competitive games, they do not allow characters to look like others, for obvious reasons. In a competitive environment opponents need to be identified. Fast. Anything such as player choose-able vanity could interfere with this and give other players an unfair advantage. Sure, games like LoL or Dota allow customisation, but it's only customisation that retains the identity of the character, preventing confusion.
In this game, where everyone could wear a bikini or a santa suit, it would be a nightmare.