The rules that use the vocabulary item "opfor" are:

<specific_platoon_type-creatable-sing>

opfor 57mm

opfor mechanized

<i_f_v-sing>

opfor 37mm

opfor 57mm

opfor apc

opfor armored personnel carrier

opfor artillery battalion fdc

opfor artillery battalion fire direction center

opfor artillery battery c2

opfor artillery battery command and control

opfor artillery battery fdc

opfor artillery battery fire direction center

opfor medium mortar

<i_f_v-pl>

opfor 37mms

opfor 57mms

opfor apcs

opfor armored personnel carriers

opfor artillery battalion fdcs

opfor artillery battalion fire direction centers

opfor artillery battery c2s

opfor artillery battery command and controls

opfor artillery battery fdcs

opfor artillery battery fire direction centers

opfor medium mortars

<specific_section_type-not_creatable-sing>

opfor a-t

opfor anti tank

opfor commando machine gun

opfor commando mg

opfor commando mortar

opfor land rover recoilless a-t

opfor land rover recoilless anti tank

opfor mortar

opfor recoilless

opfor recoilless a-t

opfor recoilless anti tank

opfor recoilless rifle

<team_or_group_company_echelon>

opfor mech heavy combat team

opfor mechanized heavy combat team

<specific_team_type-sing>

opfor 57mm

<team_or_group_section_echelon>

opfor tank combat team headquarters

opfor tank combat team hq

opfor tank team headquarters

opfor tank team hq

<specific_section_type-creatable-sing>

opfor a-t

opfor anti tank

opfor commando machine gun

opfor commando mg

opfor commando mortar

opfor land rover recoilless a-t

opfor land rover recoilless anti tank

opfor mortar

opfor recoilless

opfor recoilless a-t

opfor recoilless anti tank

opfor recoilless rifle

<specific_team_type-creatable-sing>

opfor 57mm

<i_f_v>

opfor 37mm

opfor 37mms

opfor 57mm

opfor 57mms

opfor apc

opfor apcs

opfor armored personnel carrier

opfor armored personnel carriers

opfor artillery battalion fdc

opfor artillery battalion fdcs

opfor artillery battalion fire direction center

opfor artillery battalion fire direction centers

opfor artillery battery c2

opfor artillery battery c2s

opfor artillery battery command and control

opfor artillery battery command and controls

opfor artillery battery fdc

opfor artillery battery fdcs

opfor artillery battery fire direction center

opfor artillery battery fire direction centers

opfor medium mortar

opfor medium mortars

<specific_team_type-not_creatable-sing>

opfor 57mm

<specific_section_type-sing>

opfor a-t

opfor anti tank

opfor commando machine gun

opfor commando mg

opfor commando mortar

opfor land rover recoilless a-t

opfor land rover recoilless anti tank

opfor mortar

opfor recoilless

opfor recoilless a-t

opfor recoilless anti tank

opfor recoilless rifle

<specific_platoon_type-not_creatable-sing>

opfor 57mm

opfor mechanized

<specific_platoon_type-sing>

opfor 57mm

opfor mechanized