Attribute Reference Tables
This page is based off the "attribute reference table) in the textools reference doc by sel. This information has not been validated to have been changed in dawntrail, so while nothing on here whould have changed, it is possible that some information is outdated or missing.
Mesh parts in FF14 have many types of Attributes, and these determine when and what parts of a mesh should be hidden.
Every Mesh part (X.0, X.1, etc) Has it's own list of attributes that will change what is and is not hidden when the correct metadata is combined with it. for example a mesh part with the upper arm attribute will be hidden if the item is paired with long gloves.
This is especially important when replacing the mesh parts of one model with another's, or when you are making/altering a mesh that needs to hide certain parts. If the mesh part numbers are different, then unwanted parts may hide when something is equipped. If you ever have a mod where something goes invisible when another gear piece is worn (usually long gloves) then that means that an attribute was incorrectly placed on a mesh part. likewise, if a part of the mesh does not hide when the corresponding piece is worn (like long gloves) then that means that mesh part does not have the attribute set.
Some gear uses special "Variant Attributes" such as atr_tv_a. these attributes are special as they are not decided by what other gear you have on, but rather are decided by what item variant you have equipped. What variants hide/show what items is determined by thier IMC values, which can be found in the metadata editing tabs of your chosen mod editor.
Variant attributes go from a to j (so atr_xv_b for example) with a total of 10 possible variant attributes per item, at the time of writing this.
Other variant attributes may exist for other model types, but most other model types do not have IMC files, so they will not be gone over here.
Unlisted model types have no unique attributes. Ex: Tail (til) and Ear (zir)