Arma 2 OA Command Version Reference

Arma 2 OA — SQF command version reference (A3 contrast)

Independent BIKI-verified version-evidence companion to the canonical External Arma 2 OA reference guide. That page maps concepts → references and how-to-use; this page is the dated provenance log: the first game / version of each command this fork touches, so an agent can decide at a glance whether a command is safe for the Arma 2 OA 1.63 / 1.64 target. Verified read-only against the Bohemia Community Wiki (community.bistudio.com) on 2026-06-02 — reading a command's version badge needs no account.

Why this matters

The fastest way to break OA mission SQF is to "fix" it with Arma 3 reflexes: many everyday A3 commands simply did not exist in 2010–2013 and throw undefined command errors on OA. This page is the quick yes/no, with the OA-safe replacement.

Arma 3-only — do NOT use in OA mission SQF

Command / form	First game · version	Arma 2 OA replacement
params ["_a","_b"]	Arma 3 · 1.48	private ["_a","_b"]; _a = _this select 0; _b = _this select 1;
setGroupOwner / groupOwner	Arma 3 · 1.40	No equivalent — OA cannot transfer group locality; it follows the group leader's owner. (Impacts DR-21 HC re-delegation: you can redirect future spawns to a surviving HC, but cannot transfer live AI.)
array select [start, count]	Arma 3 · 1.32	single-index select N, or build with for/forEach.
string select [start, length] (substring)	Arma 3 · 1.28	toArray / toString (no native substring in OA).
array select {expression} (filter)	Arma 3 · 1.56	{ if (cond) then { … } } forEach _arr.
array apply {expression} (map)	Arma 3 · 1.56	{ _x = f _x } forEach _arr, or build a new array in a for/forEach loop. Source has zero apply array-command uses (only the English word in comments); it previously appeared in a draft doc fix-snippet and is kept here as a regression warning.
isEqualType	Arma 3 · 1.54	typeName _x == "ARRAY" (etc.).
isEqualTo	Arma 3 · 1.16	== for simple comparable values; use isNil, typeName and explicit shape/count checks for validation. Do not use this in OA copyable snippets.
remoteExec / remoteExecCall	Arma 3 · 1.50	publicVariable + addPublicVariableEventHandler (this mission's PVF wrappers).
parseSimpleArray	Arma 3 · 1.68	call compile — trusted input only (see DR-1 / DR-7 / DR-46).
ext callExtension [fn, args] (array form)	Arma 3 · 1.68	string form: ext callExtension "code,args".
private _x = value (inline-assign)	Arma 3 style	private "_x"; _x = value;
setUnitLoadout / getUnitLoadout	Arma 3 · 1.58	No OA equivalent. OA loadouts come from config classes plus addWeapon/addMagazine/*CargoGlobal and setVehicleInit. Confirmed absent from source (0 hits): Tools/LoadoutManager generates config-driven loadouts; it does not use the A3 loadout API. Do not introduce.
hideObjectGlobal / enableSimulationGlobal	Arma 3 · 1.12	A3-only Global variants. OA only has the local hideObject / enableSimulation; the effect is per-machine and must be re-applied (or driven by the mission's PV pattern) for global state. Confirmed absent from source (0 hits) — do not introduce a Global variant by reflex.
selectRandom	Arma 3 · 1.56	Use the repo idiom _arr select floor(random count _arr) (Common/Init/Init_Town.sqf:39, Server/AI/AI_AdvancedRespawn.sqf) or _arr call BIS_fnc_selectRandom (OA-safe, see below). Confirmed absent — the 4 selectRandom source hits are all BIS_fnc_selectRandom. ⚠ Do not "simplify" call BIS_fnc_selectRandom into the selectRandom command: the function is OA-safe, the command is not.
splitString / joinString	Arma 3 · 1.50	No OA native split/join — parse with toArray/toString + a manual forEach. Confirmed absent (0 hits).
trim (+ regexFind / regexMatch)	Arma 3 · 2.02 (regex 2.x)	No OA equivalent; trim/match manually via toArray/toString. Confirmed absent.

Confirmed available in Arma 2 OA

Command / form	First · version	Note
obj getVariable ["name", default]	ArmA 1.00 (obj/group); OA 1.60 (namespace)	Default-value form is OA-safe on missionNamespace. CAVEAT: on objNull, A2 returns undefined, not the default (A3 fixed this).
obj setVariable ["name", val, true]	ArmA 1.00	Public-broadcast 3rd arg is OA-safe.
publicVariableServer / publicVariableClient	OA 1.62	client→server / server→one-client targeting.
callExtension (string form)	OA 1.60	Blocking — keep out of hot loops.
diag_tickTime	Arma 2 · 1.00	Real-time, high-precision elapsed seconds; unscaled and does not pause with game time. Commonly mis-remembered as A3-only, but it is A2-era and OA-safe — the correct clock for perf instrumentation. Repo uses it as the PerformanceAudit_Record stopwatch (~62 files, e.g. Client/Client_UpdateRHUD.sqf:187). Do not "modernize" it away.
uiSleep	Arma 2 · 1.05 (also OA 1.50)	Like sleep but not scaled by accelerated/skipped game time — suspends on real-time cadence (correct for server housekeeping loops). Also frequently assumed A3-only; it is OA-safe. Repo uses it in the AntiStack loops (Server/Module/AntiStack/mainLoop.sqf:16, flushLoop.sqf) and Server/FSM/restorers/buildings_restorer.sqf:26 (7 files).
getPosATL / setPosATL	Arma 2 · 1.03	Above-terrain-level coordinates. OA-safe (7 / 2 files).
createVehicleLocal	ArmA 1.00	Creates a client-local object not synchronized over the network (netId is 0:0) — use only for local FX/markers; other machines will not see it. 6 files.
addWeaponCargoGlobal / addMagazineCargoGlobal	OA 1.55	Global MP effect (cargo synced to all clients) — the MP-correct cargo add, not A3-only. Repo gear-equip path (Common/Functions/Common_EquipBackpack.sqf, Common_EquipVehicle.sqf).
BIS_fnc_selectRandom	Arma 2 · 1.00 (OA 1.50)	OA-safe function (_arr call BIS_fnc_selectRandom) returning a random array element — distinct from the A3-only selectRandom command in the avoid-list above. Repo: spawn-pad pick in Client/Functions/Client_BuildUnit.sqf:59/85/111/135.
allGroups, call, compile, preprocessFileLineNumbers, typeName, isNil, format, localize, hintSilent, diag_log, diag_fps, publicVariable, addPublicVariableEventHandler, toArray, toString, setVectorDirAndUp (ArmA 1.09)	OFP / ArmA / A2	All OA-safe.
BIS_fnc_arrayPush	Arma 2 · 1.00 (also OA/TOH/A3)	OA-safe function: [array, element] call BIS_fnc_arrayPush appends element to array in place. Functions-module dependent (requires BIS_fnc_init/CBA-equivalent function library loaded, standard on this fork). Verified against the BI wiki 2026-07-09.
unitsBelowHeight	Arma 2 · 1.04	group unitsBelowHeight height returns the group's units below the given height — valid A2/OA, NOT A3-only. Recorded after the 2026-07-10 bug-hunt where finder + verifier + a 2-skeptic panel ALL shared the wrong "A3-only" belief and produced two critical false positives against Common_RunCommanderTeam.sqf:2216/:2433; the command is load-bearing in town capture at 7 sites incl. server_town.sqf. Run the a2oa-verify ladder (BIKI version badge first) before shipping any "A3-only" finding on an unlisted command.

Object lifecycle commands — OA-safe, locality-sensitive

The object-lifecycle addendum is closed: these commands are valid OA-era SQF, but the important question is who owns the object and whether the effect is local or global. Current source uses the spawn/delete/init family heavily; hideObject / enableSimulation are not live source commands in this fork, and the A3 *Global variants remain absent.

Command	First · version	Repo guardrail
createVehicle	OFP / ArmA era	OA-safe global object creation. Used for server support drops (Server/Support/Support_Paratroopers.sqf:50), town depot/camp/flag objects (Common/Init/Init_Town.sqf:82,99,110) and client visual/effect paths such as nuke/UAV helpers. Authority still depends on caller path; do not treat command availability as server validation.
createUnit	OFP / ArmA era	OA-safe group/unit creation. Examples include server HQ radio logic (Server/Init/Init_Server.sqf:397-398,572) and local CoIn logic setup (Client/Module/CoIn/coin_interface.sqf:69). Locality follows the target group/owner model; OA has no setGroupOwner.
deleteVehicle	OFP / ArmA era	OA-safe deletion. Heavily used by support cleanup, CoIn preview cleanup, modules and server maintenance loops. Before patching deletion logic, check owner pages such as Town AI vehicle safety and Marker cleanup/restoration for player-cargo, marker and stale-state hazards.
hideObject / enableSimulation	OFP / ArmA / A2 era local forms	OA has local forms only. Current source has no live hideObject or enableSimulation hits, so do not introduce them as a global state fix without an explicit publicVariable/JIP replay plan.
hideObjectGlobal / enableSimulationGlobal	Arma 3 · 1.12	A3-only global variants. Confirmed absent; do not import them into OA snippets.

Object scans & spatial queries — all OA-safe; pick the right one

These are heavily used across the fork and all date to OFP/ArmA/A2, so the trap here is semantic, not version: choosing a scan whose filter silently excludes what you need.

Command	First · version	Returns / when to use	Repo
nearestObjects [pos, classes, radius]	A2 · 1.00	Array sorted by distance; isKindOf class matching; [] = all classes (slowest).	origin/master already uses class-filtered ["Base_WarfareBUAVterminal"] for the CC proximity scan (line 61) and broad [] only for the nearby-player check (line 83). Lines 24-28 are interdiction kill-reward code, not a scan. The class-filter optimization is already on master — do not re-apply it. 16 files.
nearEntities [classes, radius]	A2 · 1.00	Unsorted; alive units / vehicles / game-logics only — excludes dead objects, buildings/structures, and crew inside vehicles. BI notes it is "much faster" than nearestObjects for soldiers/vehicles.	Camp/depot/airfield proximity (nearEntities [WFBE_Logic_Camp, _range]; Client_GetClosestCamp/Depot/Airport.sqf). 39 files.
nearObjects [classes, radius]	ArmA 1.00	Unsorted radius scan, optional class filter; does include structures/dead objects.	5 files.
nearestObject	OFP 1.00	Single nearest object of a type (a hardcoded-50 m form exists).	27 files.

Guardrail (DR-39): the supply command-center scan targets the Base_WarfareBUAVterminal structure, so it cannot be "optimized" by swapping to nearEntities — that command returns no buildings and would silently match nothing. The OA-safe narrowing is a class-filtered nearestObjects (or nearObjects) plus isKindOf, not an entity scan. See Supply mission scan narrowing and Performance opportunity sweep.

OA-safe but removed in Arma 3 — the inverse trap

These commands exist and work in OA 1.64 but were disabled in Arma 3 for security. An agent porting Arma 3 reflexes can fall for the opposite of the avoid-list above — assuming they are gone or unsafe and rewriting them — when they are load-bearing in this fork. Keep them.

Command	First · version	OA status / repo use
setVehicleInit	OFP:Elite / A2 · 1.00 (OA 1.50)	OA-safe; disabled in Arma 3 (security). Global Effect — the init string is broadcast and runs on every machine. Repo passes only hardcoded literal init strings: textures via Common/Functions/Common_AddVehicleTexture.sqf, fixed init-script calls (Client/Module/UAV/uav.sqf:30, artillery in Client/Functions/Client_FNC_Special.sqf:202). Because the strings are constants, this is not a network-derived injection surface beyond the documented PVF dispatcher class (DR-1). 17 files.
processInitCommands	OFP:Elite / A2 · 1.00 (OA 1.50)	OA-safe; disabled in Arma 3. Runs the queued setVehicleInit statements once; paired immediately after setVehicleInit in Common_CreateUnit.sqf/Common_CreateVehicle.sqf, construction sites and UAV spawn. 19 files.

The MP-safe wrapper WASP_procInitComm (WASP/common/procInitComm.sqf) has been removed from initJIPCompatible.sqf in current master (it was compiled-commented-out on an earlier branch), so the mission relies on these raw calls directly — the standard A2 pattern. See WASP overlay.

Gaps folded into canonical indexes

The External Arma 2 OA reference guide now routes future agents to this page for A3-only command forms such as params, remoteExec, parseSimpleArray, setGroupOwner / groupOwner, multi-index select, filter select, apply, isEqualTo and inline private _var = value. Former apply / isEqualTo snippets in Deep-review findings have been rewritten with OA-safe forEach, isNil, typeName and == patterns.

The two inverse-trap classes are now represented in the compatibility audit and agent-compatibility-audit.json: (a) OA-safe commands commonly mis-assumed A3-only (diag_tickTime, uiSleep — both verified A2-era above), and (b) OA-safe commands removed in A3 (setVehicleInit, processInitCommands). Both classes risk a future agent "fixing" working OA code. Instructions-For-Codex item 48 is canonicalized.

Continue Reading

Canonical usage map: External Arma 2 OA reference guide · Compatibility audit: Arma 2 OA compatibility audit · Networking: Networking and public variables · Findings: Deep-review findings · Code map: SQF code atlas

Method: BIKI command pages carry a per-command version badge; that badge — not the usage examples, which often include later Arma 3 notes — is the authority for OA availability. Forum threads are corroboration only, never the version source of truth. Verified 2026-06-02, lane external-a2-docs-editorial-compression.