diff --git a/addons/api/fnc_addDisplayPassthroughKeys.sqf b/addons/api/fnc_addDisplayPassthroughKeys.sqf
index bfa0c0fa4..86eb1678d 100644
--- a/addons/api/fnc_addDisplayPassthroughKeys.sqf
+++ b/addons/api/fnc_addDisplayPassthroughKeys.sqf
@@ -16,6 +16,6 @@
  * Public: Yes
  */
 
-if (!hasInterface) exitWith {};
+if (!hasInterface) exitWith {false};
 
 _this call EFUNC(sys_core,addDisplayPassthroughKeys);
diff --git a/addons/api/fnc_addNotificationDisplay.sqf b/addons/api/fnc_addNotificationDisplay.sqf
index bb2ddb2ec..e82c7069a 100644
--- a/addons/api/fnc_addNotificationDisplay.sqf
+++ b/addons/api/fnc_addNotificationDisplay.sqf
@@ -15,7 +15,7 @@
  * Public: Yes
  */
 
-if (!hasInterface) exitWith {};
+if (!hasInterface) exitWith {-1};
 
 params [["_displayId", -1, [0]]];
 
diff --git a/addons/api/fnc_addRackToVehicle.sqf b/addons/api/fnc_addRackToVehicle.sqf
index 29debef8f..264d9d8c9 100644
--- a/addons/api/fnc_addRackToVehicle.sqf
+++ b/addons/api/fnc_addRackToVehicle.sqf
@@ -70,6 +70,7 @@ if (_forceInitialisation) then {
 
 if (!_success) exitWith {
     WARNING_1("Vehicle %1 failed to initialise",_vehicle);
+    false
 };
 
 if (count _rackConfiguration != 9) exitWith {
diff --git a/addons/api/fnc_babelAddLanguageType.sqf b/addons/api/fnc_babelAddLanguageType.sqf
index 35f323bcd..a8def1420 100644
--- a/addons/api/fnc_babelAddLanguageType.sqf
+++ b/addons/api/fnc_babelAddLanguageType.sqf
@@ -17,7 +17,7 @@
  */
 
 // Babel is not maintained on non-clients.
-if (!hasInterface) exitWith {};
+if (!hasInterface) exitWith {false};
 
 params [
     ["_languageKey", "", [""]],
diff --git a/addons/api/fnc_babelGetLanguageId.sqf b/addons/api/fnc_babelGetLanguageId.sqf
index aca9d5893..7ea688ba5 100644
--- a/addons/api/fnc_babelGetLanguageId.sqf
+++ b/addons/api/fnc_babelGetLanguageId.sqf
@@ -7,7 +7,7 @@
  * 0: Language display name <STRING>
  *
  * Return Value:
- * Language ID <STRING>
+ * Language ID (or false on bad input) <STRING><BOOL>
  *
  * Example:
  * ["English"] call acre_api_fnc_babelGetLanguageId;
diff --git a/addons/api/fnc_babelSetupMission.sqf b/addons/api/fnc_babelSetupMission.sqf
index 2555f123f..6ba5bba7d 100644
--- a/addons/api/fnc_babelSetupMission.sqf
+++ b/addons/api/fnc_babelSetupMission.sqf
@@ -10,7 +10,7 @@
  *   1: Language display name <STRING>
  *
  * Return Value:
- * Setup successful <BOOL>
+ * None
  *
  * Example:
  * [ [west, "English", "French"], [east, "Russian"], [civilian, "French"] ] call acre_api_fnc_babelSetupMission;
diff --git a/addons/api/fnc_getCurrentRadioChannelNumber.sqf b/addons/api/fnc_getCurrentRadioChannelNumber.sqf
index 1cfd15559..885af40b0 100644
--- a/addons/api/fnc_getCurrentRadioChannelNumber.sqf
+++ b/addons/api/fnc_getCurrentRadioChannelNumber.sqf
@@ -7,7 +7,7 @@
  * None
  *
  * Return Value:
- * Channel number. Returns -1 if no active radio or the channel can't be found. <NUMBER>
+ * Channel number (or array for PRC77). Returns -1 if no active radio or the channel can't be found. <NUMBER><ARRAY>
  *
  * Example:
  * [] call acre_api_fnc_getCurrentRadioChannelNumber;
diff --git a/addons/api/fnc_getMountedRackRadio.sqf b/addons/api/fnc_getMountedRackRadio.sqf
index d028da381..324172630 100644
--- a/addons/api/fnc_getMountedRackRadio.sqf
+++ b/addons/api/fnc_getMountedRackRadio.sqf
@@ -22,6 +22,7 @@ params [
 
 if (!([_rackId] call EFUNC(sys_radio,radioExists))) exitWith {
     WARNING_1("Non existant rack ID provided: %1",_rackId);
+    ""
 };
 
 private _return = "";
diff --git a/addons/api/fnc_getRadioByType.sqf b/addons/api/fnc_getRadioByType.sqf
index 293b0cacf..3a63e0df6 100644
--- a/addons/api/fnc_getRadioByType.sqf
+++ b/addons/api/fnc_getRadioByType.sqf
@@ -9,7 +9,7 @@
  * 1: Optional unit or List of String <ARRAY, OBJECT> (default: [])
  *
  * Return Value:
- * Radio ID <STRING>
+ * Radio ID (or nil if not found) <STRING><NIL>
  *
  * Example:
  * _radioId = ["ACRE_PRC152"] call acre_api_fnc_getRadioByType
diff --git a/addons/api/fnc_getRadioChannel.sqf b/addons/api/fnc_getRadioChannel.sqf
index fa484beed..14c0c8749 100644
--- a/addons/api/fnc_getRadioChannel.sqf
+++ b/addons/api/fnc_getRadioChannel.sqf
@@ -7,7 +7,7 @@
  * 0: Radio ID <STRING>
  *
  * Return Value:
- * Channel number, 1-N depending on the radio <NUMBER>
+ * Channel number, 1-N depending on the radio (or array for PRC77) <NUMBER><ARRAY>
  *
  * Example:
  * _currentChannel = ["ACRE_PRC152_ID_123"] call acre_api_fnc_getRadioChannel;
diff --git a/addons/api/fnc_getRadioOnOffState.sqf b/addons/api/fnc_getRadioOnOffState.sqf
index 247796002..25e812ba0 100644
--- a/addons/api/fnc_getRadioOnOffState.sqf
+++ b/addons/api/fnc_getRadioOnOffState.sqf
@@ -7,7 +7,7 @@
  * 0: Radio ID <STRING>
  *
  * Return Value:
- * TRUE if radio is ON, False if the radio is OFF <BOOLEAN>
+ * TRUE if radio is ON, False if the radio is OFF (or -1 if not valid) <BOOLEAN><NUMBER>
  *
  * Example:
  * ["ACRE_PR77_ID_1"] call acre_api_fnc_getRadioOnOffState
diff --git a/addons/api/fnc_getRevealToAI.sqf b/addons/api/fnc_getRevealToAI.sqf
index 903987eb8..d2c6c27eb 100644
--- a/addons/api/fnc_getRevealToAI.sqf
+++ b/addons/api/fnc_getRevealToAI.sqf
@@ -7,7 +7,7 @@
  * None
  *
  * Return Value:
- * AI enabled <NUMBER>
+ * AI enabled (or false if setting not ready) <NUMBER><BOOL>
  *
  * Example:
  * [] call acre_api_fnc_getRevealToAI;
diff --git a/addons/api/fnc_getVehicleRacks.sqf b/addons/api/fnc_getVehicleRacks.sqf
index 5eac9143b..67183607c 100644
--- a/addons/api/fnc_getVehicleRacks.sqf
+++ b/addons/api/fnc_getVehicleRacks.sqf
@@ -21,6 +21,7 @@ params [
 
 if (isNull _vehicle) exitWith {
     WARNING_1("Vehicle %1 not defined.",_vehicle);
+    []
 };
 
 [_vehicle] call EFUNC(sys_rack,getVehicleRacks)
diff --git a/addons/api/fnc_removeAllRacksFromVehicle.sqf b/addons/api/fnc_removeAllRacksFromVehicle.sqf
index 2d1f3ed57..63aebb008 100644
--- a/addons/api/fnc_removeAllRacksFromVehicle.sqf
+++ b/addons/api/fnc_removeAllRacksFromVehicle.sqf
@@ -38,6 +38,7 @@ if (!([_vehicle] call FUNC(areVehicleRacksInitialized))) then {
 
 if (!_success) exitWith {
     WARNING_1("Vehicle %1 failed to initialise",_vehicle);
+    false
 };
 
 [{
diff --git a/addons/api/fnc_setPresetChannelData.sqf b/addons/api/fnc_setPresetChannelData.sqf
index 187388b90..e347ab75a 100644
--- a/addons/api/fnc_setPresetChannelData.sqf
+++ b/addons/api/fnc_setPresetChannelData.sqf
@@ -19,3 +19,5 @@
  *
  * Public: Yes
  */
+
+false // not implemented
diff --git a/addons/api/fnc_setPresetChannelField.sqf b/addons/api/fnc_setPresetChannelField.sqf
index da3417c08..f6521306e 100644
--- a/addons/api/fnc_setPresetChannelField.sqf
+++ b/addons/api/fnc_setPresetChannelField.sqf
@@ -7,7 +7,7 @@
  * Arguments:
  * 0: Radio Base class <STRING>
  * 1: Preset name <STRING>
- * 2: Channel number <NUMBER>
+ * 2: Channel number <NUMBER><STRING>
  * 3: Field name <STRING>
  * 4: value <ANY>
  *
diff --git a/addons/sys_bf888s/functions/fnc_render.sqf b/addons/sys_bf888s/functions/fnc_render.sqf
index b132282e8..c4e0b702d 100644
--- a/addons/sys_bf888s/functions/fnc_render.sqf
+++ b/addons/sys_bf888s/functions/fnc_render.sqf
@@ -4,7 +4,7 @@
  * Renders the radio when opened.
  *
  * Arguments:
- * 0: Display identifier <NUMBER>
+ * 0: Display <DISPLAY>
  *
  * Return Value:
  * True <BOOL>
diff --git a/addons/sys_core/fnc_getLanguageName.sqf b/addons/sys_core/fnc_getLanguageName.sqf
index 113d344ab..75e0a2bfc 100644
--- a/addons/sys_core/fnc_getLanguageName.sqf
+++ b/addons/sys_core/fnc_getLanguageName.sqf
@@ -4,7 +4,7 @@
  * Get the language display name from the language key.
  *
  * Arguments:
- * 0: Language key <STRING>
+ * 0: Language key or index <STRING><NUMBER>
  *
  * Return Value:
  * Language display name ("" if not found) <STRING>
diff --git a/addons/sys_core/fnc_inZeus.sqf b/addons/sys_core/fnc_inZeus.sqf
index 0b8754a86..499c6dce9 100644
--- a/addons/sys_core/fnc_inZeus.sqf
+++ b/addons/sys_core/fnc_inZeus.sqf
@@ -3,6 +3,9 @@
  * Author: Brett Mayson
  * Checks if the local player is in the Zeus interface.
  *
+ * Arguments:
+ * None
+ *
  * Return Value:
  * In Zeus Interface <BOOL>
  *
diff --git a/addons/sys_core/fnc_setLossModelScale.sqf b/addons/sys_core/fnc_setLossModelScale.sqf
index 1a3a6c908..ce5d7ad85 100644
--- a/addons/sys_core/fnc_setLossModelScale.sqf
+++ b/addons/sys_core/fnc_setLossModelScale.sqf
@@ -7,7 +7,7 @@
  * 0: Terrain loss scale (value between 0 and 1) <NUMBER>
  *
  * Return Value:
- * Terrain loss scale <NUMBER>
+ * Terrain loss scale (or false on headless) <NUMBER><BOOL>
  *
  * Example:
  * [0.5] call acre_sys_core_fnc_setLossModelScale
diff --git a/addons/sys_core/fnc_setRevealToAI.sqf b/addons/sys_core/fnc_setRevealToAI.sqf
index 0bf77d7ae..16c679f68 100644
--- a/addons/sys_core/fnc_setRevealToAI.sqf
+++ b/addons/sys_core/fnc_setRevealToAI.sqf
@@ -8,7 +8,7 @@
  * 0: Reveal factor players to AI that speak <NUMBER>
  *
  * Return Value:
- * Reveal factor for revealing players to AI <NUMBER>
+ * Reveal factor for revealing players to AI (or false on headless) <NUMBER><BOOL>
  *
  * Example:
  * _status = [0.5] call acre_sys_core_fnc_setRevealToAI
diff --git a/addons/sys_external/fnc_checkReturnGive.sqf b/addons/sys_external/fnc_checkReturnGive.sqf
index bca050d6e..2c0d7121d 100644
--- a/addons/sys_external/fnc_checkReturnGive.sqf
+++ b/addons/sys_external/fnc_checkReturnGive.sqf
@@ -4,8 +4,8 @@
  * Check if a radio being used externally is being returned to the owner or given to another unit.
  *
  * Arguments:
- * 1: Unique radio ID <STRING>
- * 0: Unit to be given/returned a radio <OBJECT>
+ * 0: Unique radio ID <STRING>
+ * 1: Unit to be given/returned a radio <OBJECT>
  *
  * Return Value:
  * Radio is returned (true) or given (false) <BOOL>
diff --git a/addons/sys_gestures/fnc_startedSpeaking.sqf b/addons/sys_gestures/fnc_startedSpeaking.sqf
index 416ec7447..190b2dc6b 100644
--- a/addons/sys_gestures/fnc_startedSpeaking.sqf
+++ b/addons/sys_gestures/fnc_startedSpeaking.sqf
@@ -6,7 +6,7 @@
  * Arguments:
  * 0: Unit that started speaking <OBJECT>
  * 1: Is unit on radio <BOOL>
- * 2: Radio unit is currently using <OBJECT>
+ * 2: Radio unit is currently using <STRING>
  *
  * Return Value:
  * None
diff --git a/addons/sys_gui/fnc_showVehicleInfo.sqf b/addons/sys_gui/fnc_showVehicleInfo.sqf
index 3e9128027..b9b362c66 100644
--- a/addons/sys_gui/fnc_showVehicleInfo.sqf
+++ b/addons/sys_gui/fnc_showVehicleInfo.sqf
@@ -4,13 +4,13 @@
  * Show or hide Vehicle Info UI.
  *
  * Arguments:
- * 0: Player <OBJECT>
+ * 0: Show <BOOL>
  *
  * Return Value:
  * None
  *
  * Example:
- * [player] call acre_sys_gui_fnc_showVehicleInfo
+ * [true] call acre_sys_gui_fnc_showVehicleInfo
  *
  * Public: No
  */
diff --git a/addons/sys_intercom/vic3/fnc_vic3ffcsRender.sqf b/addons/sys_intercom/vic3/fnc_vic3ffcsRender.sqf
index 45080e81f..451b22d29 100644
--- a/addons/sys_intercom/vic3/fnc_vic3ffcsRender.sqf
+++ b/addons/sys_intercom/vic3/fnc_vic3ffcsRender.sqf
@@ -4,7 +4,7 @@
  * Renders the VIC3 FFCS when opened.
  *
  * Arguments:
- * 0: Display identifier <NUMBER>
+ * 0: Display identifier <DISPLAY>
  *
  * Return Value:
  * True <BOOL>
diff --git a/addons/sys_list/fnc_addDisplaySupport.sqf b/addons/sys_list/fnc_addDisplaySupport.sqf
index 64da2f78c..b394573ab 100644
--- a/addons/sys_list/fnc_addDisplaySupport.sqf
+++ b/addons/sys_list/fnc_addDisplaySupport.sqf
@@ -8,7 +8,7 @@
  * 0: Display ID <NUMBER>
  *
  * Return Value:
- * None
+ * Index <NUMBER>
  *
  * Example:
  * [312] call acre_sys_list_fnc_addDisplaySupport
diff --git a/addons/sys_prc343/functions/fnc_render.sqf b/addons/sys_prc343/functions/fnc_render.sqf
index fb129e53a..e326d6280 100644
--- a/addons/sys_prc343/functions/fnc_render.sqf
+++ b/addons/sys_prc343/functions/fnc_render.sqf
@@ -4,7 +4,7 @@
  * Renders the radio when opened.
  *
  * Arguments:
- * 0: Display identifier <NUMBER>
+ * 0: Display <DISPLAY>
  *
  * Return Value:
  * True <BOOL>
diff --git a/addons/sys_prc77/functions/fnc_render.sqf b/addons/sys_prc77/functions/fnc_render.sqf
index 06f6807b6..4ba3fe201 100644
--- a/addons/sys_prc77/functions/fnc_render.sqf
+++ b/addons/sys_prc77/functions/fnc_render.sqf
@@ -4,7 +4,7 @@
  * Renders the radio when opened.
  *
  * Arguments:
- * 0: Display identifier <NUMBER>
+ * 0: Display <DISPLAY>
  *
  * Return Value:
  * True <BOOL>
diff --git a/addons/sys_prc77/radio/fnc_handleEndTransmission.sqf b/addons/sys_prc77/radio/fnc_handleEndTransmission.sqf
index 9af8da19c..e70808fdf 100644
--- a/addons/sys_prc77/radio/fnc_handleEndTransmission.sqf
+++ b/addons/sys_prc77/radio/fnc_handleEndTransmission.sqf
@@ -7,7 +7,7 @@
  * Arguments:
  * 0: Radio ID <STRING>
  * 1: Event: "handleEndTransmission" <STRING> (Unused)
- * 2: Event data with transmitting ID <STRING>
+ * 2: Event data with transmitting ID <ARRAY>
  * 3: Radio data <HASH> (Unused)
  * 4: Remote <BOOL> (Unused)
  *
diff --git a/addons/sys_prc77/radio/fnc_setCurrentChannel.sqf b/addons/sys_prc77/radio/fnc_setCurrentChannel.sqf
index 49fb67cbd..d326062bc 100644
--- a/addons/sys_prc77/radio/fnc_setCurrentChannel.sqf
+++ b/addons/sys_prc77/radio/fnc_setCurrentChannel.sqf
@@ -6,7 +6,7 @@
  * Arguments:
  * 0: Radio ID <STRING>
  * 1: Event: "setCurrentChannel" <STRING> (Unused)
- * 2: Event data <NUMBER>
+ * 2: Event data <ARRAY>
  * 3: Radio data <HASH>
  * 4: Remote <BOOL> (Unused)
  *
diff --git a/addons/sys_rack/fnc_configWiredIntercoms.sqf b/addons/sys_rack/fnc_configWiredIntercoms.sqf
index 4b7b5ff67..b1386c23e 100644
--- a/addons/sys_rack/fnc_configWiredIntercoms.sqf
+++ b/addons/sys_rack/fnc_configWiredIntercoms.sqf
@@ -5,7 +5,7 @@
  *
  * Arguments:
  * 0: Vehicle <OBJECT>
- * 1: Rack class <STRING>
+ * 1: Rack class <CONFIG>
  *
  * Return Value:
  * Wired Intercoms <ARRAY>
diff --git a/addons/sys_rack/fnc_getRackBaseClassname.sqf b/addons/sys_rack/fnc_getRackBaseClassname.sqf
index 350c9cb36..0697813c4 100644
--- a/addons/sys_rack/fnc_getRackBaseClassname.sqf
+++ b/addons/sys_rack/fnc_getRackBaseClassname.sqf
@@ -7,7 +7,7 @@
  * 0: Classname <STRING>
  *
  * Return Value:
- * Is Unique <BOOL>
+ * Base classname <STRING>
  *
  * Example:
  * ["acre_vrc111_id_1"] call acre_sys_rack_fnc_getRackBaseClassname
diff --git a/addons/sys_radio/fnc_getRadioBaseClassname.sqf b/addons/sys_radio/fnc_getRadioBaseClassname.sqf
index 5a5548553..4178f4cce 100644
--- a/addons/sys_radio/fnc_getRadioBaseClassname.sqf
+++ b/addons/sys_radio/fnc_getRadioBaseClassname.sqf
@@ -7,7 +7,7 @@
  * 0: Classname <STRING>
  *
  * Return Value:
- * Is Unique <BOOL>
+ * Base classname <STRING>
  *
  * Example:
  * ["acre_prc152_id_1"] call acre_sys_radio_fnc_getRadioBaseClassname
diff --git a/addons/sys_radio/fnc_onReturnRadioId.sqf b/addons/sys_radio/fnc_onReturnRadioId.sqf
index ca0e2a0c5..40c622c25 100644
--- a/addons/sys_radio/fnc_onReturnRadioId.sqf
+++ b/addons/sys_radio/fnc_onReturnRadioId.sqf
@@ -7,7 +7,7 @@
  * 0: Player <OBJECT>
  * 1: Base radio class <STRING>
  * 2: Return ID number <NUMBER>
- * 3: Replacement number <NUMBER>
+ * 3: Replacement ID <STRING>
  *
  * Return Value:
  * RETURN VALUE <TYPE>
diff --git a/addons/sys_radio/fnc_setRadioOpenState.sqf b/addons/sys_radio/fnc_setRadioOpenState.sqf
index bdbce82a0..32d634c99 100644
--- a/addons/sys_radio/fnc_setRadioOpenState.sqf
+++ b/addons/sys_radio/fnc_setRadioOpenState.sqf
@@ -8,7 +8,7 @@
  * 1: Radio open state <BOOL>
  *
  * Return Value:
- * Can open radio <BOOL>
+ * None
  *
  * Example:
  * ["acre_prc152_id_1", false] call acre_sys_radio_fnc_setRadioOpenState