update readme

EVENTS.md

@@ -149,6 +149,9 @@ end
 Fire when a spell cast applies an aura. "Self" covers casts that land on the active player (including cases where the active player is the caster with no explicit target); "Other" covers all other targets.
 
 These events are gated behind the `NP_EnableAuraCastEvents` CVar (default 0). Set it to `1` to enable.
+**Note:** some auras do not have spell effects and won’t trigger these events; the BUFF/DEBUFF gain events are the only way to track those.
+
+These events are primarily intended for basic tracking of aura applications when buff/debuff caps prevent normal GAINS events from firing.
 
 Parameters:
 1.  int spellId

README.md

@@ -142,7 +142,7 @@ Available events:
 - SPELL_CAST_EVENT - Fires when you cast a spell with additional information
 - SPELL_DAMAGE_EVENT_SELF and SPELL_DAMAGE_EVENT_OTHER - Combat damage events
 - Buff/Debuff Events (BUFF_ADDED_SELF, BUFF_REMOVED_SELF, etc.)
-- AURA_CAST_ON_SELF and AURA_CAST_ON_OTHER - Aura application events (fires once per aura effect; "Self" fires when the aura lands on the active player, including self-cast with no explicit target; includes aura metadata + amplitude/misc + aura cap bitfield for buff/debuff slots); set `NP_EnableAuraCastEvents=1` to enable
+- AURA_CAST_ON_SELF and AURA_CAST_ON_OTHER - Aura application events (fires once per aura effect; "Self" fires when the aura lands on the active player, including self-cast with no explicit target; includes aura metadata + amplitude/misc + aura cap bitfield for buff/debuff slots). Some auras don’t have spell effects and won’t trigger this; use BUFF/DEBUFF gains for those. Set `NP_EnableAuraCastEvents=1` to enable.
 - UNIT_DIED - Fires when a unit dies
 
 ## Bug Reporting