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

<unit_n>

<force> <force_word>

<force> unit

<force> units

<n>

<force> <full_unit_call_sign>

<unit_n-not_det-pl>

<force> <force_word-pl>

<force> units

<vehicle-not_creatable-pl>

<force> <vehicle_id-not_creatable-pl>

<unit_n-sing>

<force> <force_word-sing>

<force> unit

<aircraft-not_creatable>

<force> <aircraft_id-not_creatable>

<n-proper_name-sing-unit>

<force> <full_unit_call_sign>

<n-sing-unit>

<force> <full_unit_call_sign>

<item_n-sing>

<force> <loadable_item-sing>

<n-sing>

<force> <full_unit_call_sign>

<unit_n-not_det-sing>

<force> <force_word-sing>

<force> unit

<n-unit>

<force> <full_unit_call_sign>

<n-proper_name-sing>

<force> <full_unit_call_sign>

<unit-gapsout_null-gapsin_null-sing>

<force> <full_unit_call_sign>

<aircraft-not_creatable-pl>

<force> <aircraft_id-not_creatable-pl>

<n-proper_name>

<force> <full_unit_call_sign>

<unit-gapsout_null-gapsin_null>

<force> <full_unit_call_sign>

<unit_n-pl>

<force> <force_word-pl>

<force> units

<n-proper_name-unit>

<force> <full_unit_call_sign>

<flight-not_creatable-sing>

<force> <flight_id-not_creatable-sing>

<item_n>

<force> <loadable_item>

<vehicle-not_creatable-sing>

<force> <vehicle_id-not_creatable-sing>

<vehicle-not_creatable>

<force> <vehicle_id-not_creatable>

<flight-not_creatable>

<force> <flight_id-not_creatable>

<flight-not_creatable-pl>

<force> <flight_id-not_creatable-pl>

<aircraft-not_creatable-sing>

<force> <aircraft_id-not_creatable-sing>