In both Pathfinder and D&D 3.5e that it’s based on, abilities are often tagged as extraordinary (Ex), supernatural (Su), or spell-like (Sp). There are a few other categories (e.g. psi-like abilities, marked Ps), and some things that either go unlabeled or have their own category (e.g. spells).
Both games also have feats, special abilities that can be selected once every few levels by those who meet their requirements.
In 3.5, there is a lot of precedence suggesting that feats are extraordinary (Ex) unless the feat description and/or the description of its explicitly says otherwise. Book of Exalted Deeds suggests it by specifying that Exalted feats are supernatural, unlike other feats. Complete Champion does likewise with a number of its Domain feats. In fact, I could swear I remember reading an explicit statement to this effect.
In Pathfinder, things seem vaguer, and I cannot find any statement about the default category of feats (though, I also cannot find any such statement in 3.5e).
Does anyone know if there are any explicit statements in the published rules for these systems that feats are extraordinary unless otherwise specified? An acceptable answer must address both systems, and must either cite a quotation from an authoritative source or else indicate how sure we can be that there is no such default for each system.