The rules that use the category "<item_n>" are:

<item>

<item_n>

<item_n> <point_location_mod-gapsout_null-gapsin_null>

<item-not_call_sign>

<item_n>

<item_n> <point_location_mod-gapsout_null-gapsin_null>

<new_item>

<det-indef> <item_n>

<item_n>