coronation_self_crowning_trigger

coronation_self_crowning_trigger = {
	exists = involved_activity
	involved_activity.activity_host = {
		OR = {
			coronation_proper_artifact_crown_trigger = yes
			AND = {
				coronation_proper_artifact_regalia_trigger = no
				any_character_artifact = {
					artifact_slot_type = helmet
				}
				#Doesn't have title regalia
				save_temporary_scope_as = host_temp
				NOT = {
					any_character_artifact = {
						artifact_slot_type = regalia
						has_variable = artifact_succession_title
						var:artifact_succession_title = {
							this = scope:host_temp.primary_title
						}
					}
				}
			}
		}
	}
}

As written in game/common/scripted_triggers/10_ach_scripted_triggers.txt.