ItemPropertySpellImmunitySchool

// Returns Item property spell immunity vs. spell school. You must specify the // school to which the user will be immune(IP_CONST_SPELLSCHOOL_*). itemproperty ItemPropertySpellImmunitySchool(int nSchool);

Note: It is not clear why the values for IP_CONST_SPELLSCHOOL_* are not aligned with SPELL_SCHOOL_* for those saves which are common to both