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, bookType);

ArgumentsEdit

spellID 

Number: spellbook slot index, ascending from 1.

bookType 

Either BOOKTYPE_SPELL ("spell") or BOOKTYPE_PET ("pet"). "spell" is linked to your General Spellbook tab.

ReturnsEdit

isPassive 

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

DetailsEdit

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)