API IsPassiveSpell

Returns whether the icon in your spellbook is a Passive ability (not necessarily a spell). (And actually noted as so in spellbook) isPassive = IsPassiveSpell(spellId or index, bookType);

Arguments
(spellId)
 * spellId : Number - spell ID to query.

(index, bookType)
 * index : Number - spellbook slot index, ascending from 1.
 * bookType : String - Either BOOKTYPE_SPELL ("spell") or BOOKTYPE_PET ("pet"). "spell" is linked to your General Spellbook tab.

Returns

 * isPassive : Flag : 1 if the spell is passive, nil otherwise.

Details

 * With my Human Paladin, here are the "spells" I found to be Passive:
 * Block (Passive)
 * Diplomacy (Racial Passive)
 * Dodge (Passive)
 * Mace Specialization (Passive)
 * Parry (Passive)
 * Sword Specialization (Passive)
 * The Human Spirit (Racial Passive)