Can someone give me a rundown what makes BY_CATEGORY, BY_TYPE and BY_TOKEN mean in interactions? Wiki isn't helping.
If you look at the vanilla body_default file, like this entry;
[BODY:BASIC_2PARTBODY]
[BP:
UB:upper body:upper bodies]
[UPPERBODY][CATEGORY:BODY_UPPER] [DEFAULT_RELSIZE:1000]
[BP:
LB:lower body:lower bodies][CON:UB]
[LOWERBODY][CATEGORY:BODY_LOWER] [DEFAULT_RELSIZE:1000]
BY_CATEGORY is looking for the CATEGORY of a body part. Categories are arbitrary strings like creature classes or names, and any part that matches the BY_CATEGORY string will be flagged as a target for whatever you were doing.
BY_TYPE are functional tokens, like the GRASP token makes a part able to grab things, STANCE parts will be used to stand and walk, UNDER_PRESSURE makes an internal part able to be 'spilled' by an attack, UPPER_BODY parts are the 'main' or 'base' part of a creature, and so on.
BY_TOKEN is actually calling for an ID, the first string after BP in defining a new part, which identifies that specific part. You can have multiple parts using the same CATEGORY, but they should each be given a unique ID. That way you can attach the right hand to the right arm without also adding one to the left arm, because right and left arms will have the same category and type tokens. Parts in different categories might contain the same TYPE tokens, though, and a part can have more than one type token, like a grasp part can also be a stance part.