Terminology. Why does it bug me and others?

[Nanga]

I thought DD meand Damage Dealer, as in a class/job who's role is to... Deal damage hehe...

While DPS means Damage Per Second, which is basically means the amount of damage you deal over time.
The term DPS can be used on any job or class. Example: A WHM spamming stone is DPSing for X.

While DD can not. A WHM is not a DD, but can does DPS.

Damage Dealer is a more "casual" reference from DD, but the true roots of DD in RPG games has its definition as, "direct damage".

[Raxion]

Damage Dealer is a more "casual" reference from DD, but the true roots of DD in RPG games has its definition as, "direct damage".

In FFXI the term "DD" did indeed stand for "Damage Dealer". The term "DPS" was barely even used in FFXI. I'm not sure I even heard the term "DPS" used until I started playing WoW back in BC. There weren't any damage meters in FFXI that I know of, so the term really didn't have much of a place.

As for "DD" standing for "direct damage", I've never heard of that at all.

[Nanga]

As for "DD" standing for "direct damage", I've never heard of that at all.

Maybe you haven't been on this planet long enough? Dungeons and Dragons uses it (the first mainstream RPG, and we did it all on paper), M:TG uses it, and yes, even FF. Of course, I'll just provide a fan link to FFXI since you think it never existed in FFXI as a fan or player term:

http://ffxi.allakhazam.com/wiki/Direct_Damage

Here's another one, where Black Magic in Final Fantasy dating back to as early as FFIV, used the "Direct Damage" terminology.

http://finalfantasy.wikia.com/wiki/Black_Magic