Final Fantasy XI stats

Like most games in the Final Fantasy series, Final Fantasy XI has a number of Stats for every character, monster, and battle object in the game. The sheer size and complexity of the game however means that it has rather more of them than usual. This is an attempt at a comprehensive list and a brief description of what they do (more comprehensive information, when known, should be found on the linked stat pages).

Job Trait Stats
Traits that job traits raise above the base of 0, but nearly every single one of them is found on equipment too.

Miscellaneous Job Trait-Related Stats
Note that equipment that increases these stats will cause them to take effect even without the associated job trait.

Also note that not every job trait is a stat; many job traits are just static modifiers to a stat (for example, Clear Mind is just a bonus to the MP recovered while healing stat).

Special Traits
Numerical traits that only appear on equipment (including Atmas and Atmacites). No job gains these stats as traits.

Invisible Player-Only Stats
All of these stats are invisible. None of them need to be on monsters.

Pet-Related Stats
Monster pets are not handled the same way as player pets are and therefore have no need of these stats. Monster avatars, for example, do not consume their Summoner's MP. The dev team even admitted that Astral Flow doesn't do anything at all for monsters and their apparent use of it is actually all just monster scripting.

Pet Stats
Note that just like other stats, these stats are affected by the player's CURRENT equipment, not the equipment worn when the pet was called. There ARE some equipment pet bonuses that only matter at pet calling time, but they are for the most part not numerical in nature. Changes to the pet's stats effected by equipment changes seem to take place within a tick.

Intermediate Stats
Although the exact inner workings of the game's calculations are not known (and can't ever be known, unless the server's code is released to the public somehow), attempts at figuring out the game's workings have resulted in discovering certain formula and order of steps that have been broadly agreed on. There are therefore certain intermediate quantities that are agreed to exist, but have no official names, since there are no game effects whose description refers to them directly. And since they are variables lasting less than the length of a single attack, you can't look them up in the stats screen either. Therefore, the playerbase has managed to more or less agree on the given intermediate names.