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 appears only in a draft doc fix-snippet (Deep-Review-Findings Fix-2), so do not let it leak into a real OA patch.
isEqualType	Arma 3 · 1.54	typeName _x == "ARRAY" (etc.).
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;

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).
allGroups, call, compile, preprocessFileLineNumbers, typeName, isNil, format, localize, hintSilent, diag_log, diag_fps, publicVariable, addPublicVariableEventHandler, toArray, toString	OFP / ArmA / A2	All OA-safe.

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) is compiled commented-out (initJIPCompatible.sqf:241-245), 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 avoid-list currently names params, remoteExec, parseSimpleArray, isEqualTo, private _var = value. It should also name setGroupOwner / groupOwner (A3 1.40, no OA equivalent), the select [start,count] / substring / filter forms (A3 1.28–1.56) and apply (A3 1.56 — now added above, per Instructions-For-Codex item 42) — all easy to import by reflex, and apply appeared in a draft fix-snippet for this fork.

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.