This is used by clerics that have holy items other than a holy symbol, such as vestments, holy swords and the like. It is one slot for clerics and similar holy people, and is a WIS check. It is unlikely non-priest characters will have it. The description is below.
Craft Holy Item: If a cleric takes this proficiency, he may take an unlimited number of weaponsmithing, armorer, crafting, and the like proficiencies, as long as he has the slots for them. He will not have to add any additional slots if the proficiency is normally not allowed for clerics. A typical holy weapon (or other item) creation set of rolls will require a Craft Holy Item roll, a Weaponsmithing roll, a Sanctify roll, and a weapon enchantment spell (such as Imbue Weapon +1.) A cleric with Craft Magical Item can add an additional 10% to an Imbue Spell’s chance to be permanent without casting a permanency. Clerics always know if their enchantments are successful. Note that all pluses to permanency stack. Craft Magical Item can be used for either Mage magic items or Clerical ones. Craft Holy Item only works for Clerical ones.