diff --git a/OpenRA.Mods.Common/FileSystem/ContentInstallerFileSystemLoader.cs b/OpenRA.Mods.Common/FileSystem/ContentInstallerFileSystemLoader.cs
index c9c9310eeb..6ca45e7e64 100644
--- a/OpenRA.Mods.Common/FileSystem/ContentInstallerFileSystemLoader.cs
+++ b/OpenRA.Mods.Common/FileSystem/ContentInstallerFileSystemLoader.cs
@@ -13,23 +13,28 @@ using System.Collections.Generic;
 
 namespace OpenRA.Mods.Common.FileSystem
 {
+	[Desc("A file system that loads game assets installed by the user into their support directory.")]
 	public class ContentInstallerFileSystemLoader : IFileSystemLoader, IFileSystemExternalContent
 	{
 		[FieldLoader.Require]
+		[Desc("Mod to use for content installation.")]
 		public readonly string ContentInstallerMod = null;
 
 		[FieldLoader.Require]
-		public readonly Dictionary<string, string> Packages = null;
+		[Desc("A list of mod-provided packages. Anything required to display the initial load screen must be listed here.")]
+		public readonly Dictionary<string, string> SystemPackages = null;
 
+		[Desc("A list of user-installed packages. If missing (and not marked as optional), these will trigger the content installer.")]
 		public readonly Dictionary<string, string> ContentPackages = null;
 
-		public readonly Dictionary<string, string> ContentFiles = null;
+		[Desc("Files that aren't mounted as packages, but still need to trigger the content installer if missing.")]
+		public readonly Dictionary<string, string> RequiredContentFiles = null;
 
-		bool contentAvailable = true;
+		bool isContentAvailable = true;
 
 		public void Mount(OpenRA.FileSystem.FileSystem fileSystem, ObjectCreator objectCreator)
 		{
-			foreach (var kv in Packages)
+			foreach (var kv in SystemPackages)
 				fileSystem.Mount(kv.Key, kv.Value);
 
 			if (ContentPackages != null)
@@ -42,23 +47,23 @@ namespace OpenRA.Mods.Common.FileSystem
 					}
 					catch
 					{
-						contentAvailable = false;
+						isContentAvailable = false;
 					}
 				}
 			}
 
-			if (ContentFiles != null)
-				foreach (var kv in ContentFiles)
+			if (RequiredContentFiles != null)
+				foreach (var kv in RequiredContentFiles)
 					if (!fileSystem.Exists(kv.Key))
-						contentAvailable = false;
+						isContentAvailable = false;
 		}
 
 		bool IFileSystemExternalContent.InstallContentIfRequired(ModData modData)
 		{
-			if (!contentAvailable)
+			if (!isContentAvailable)
 				Game.InitializeMod(ContentInstallerMod, new Arguments());
 
-			return !contentAvailable;
+			return !isContentAvailable;
 		}
 	}
 }
diff --git a/mods/cnc/mod.yaml b/mods/cnc/mod.yaml
index 896b27cfe5..325b07df1d 100644
--- a/mods/cnc/mod.yaml
+++ b/mods/cnc/mod.yaml
@@ -8,7 +8,7 @@ Metadata:
 PackageFormats: Mix
 
 FileSystem: ContentInstallerFileSystem
-	Packages:
+	SystemPackages:
 		^EngineDir
 		$cnc: cnc
 		^EngineDir|mods/common: common
@@ -30,6 +30,7 @@ FileSystem: ContentInstallerFileSystem
 		~content|scores-covertops.mix
 		~content|transit.mix
 		~content|general.mix
+		# Below are mod-provided (system) packages that need to be loaded after the content packages so they can override content assets.
 		cnc|bits/snow.mix
 		cnc|bits
 		cnc|bits/jungle
diff --git a/mods/d2k/mod.yaml b/mods/d2k/mod.yaml
index 9a45c7dee1..7584145fe9 100644
--- a/mods/d2k/mod.yaml
+++ b/mods/d2k/mod.yaml
@@ -8,7 +8,7 @@ Metadata:
 PackageFormats: D2kSoundResources
 
 FileSystem: ContentInstallerFileSystem
-	Packages:
+	SystemPackages:
 		^EngineDir
 		$d2k: d2k
 		^EngineDir|mods/common: common
@@ -21,8 +21,9 @@ FileSystem: ContentInstallerFileSystem
 		content|GAMESFX
 		~content|Music
 		~content|Movies
+		# Below are mod-provided (system) packages that need to be loaded after the content packages so they can override content assets.
 		d2k|bits
-	ContentFiles:
+	RequiredContentFiles:
 		content|BLOXBASE.R16
 		content|BLOXBAT.R16
 		content|BLOXBGBS.R16
diff --git a/mods/ra/mod.yaml b/mods/ra/mod.yaml
index e143a74fe7..5b3d330db3 100644
--- a/mods/ra/mod.yaml
+++ b/mods/ra/mod.yaml
@@ -8,7 +8,7 @@ Metadata:
 PackageFormats: Mix
 
 FileSystem: ContentInstallerFileSystem
-	Packages:
+	SystemPackages:
 		^EngineDir
 		$ra: ra
 		^EngineDir|mods/common: common
@@ -36,9 +36,10 @@ FileSystem: ContentInstallerFileSystem
 		~content|movies
 		~content|scores.mix
 		~content|general.mix
+		# Below are mod-provided (system) packages that need to be loaded after the content packages so they can override content assets.
 		ra|bits
 		ra|bits/desert
-	ContentFiles:
+	RequiredContentFiles:
 		content|expand/chrotnk1.aud
 		content|expand/fixit1.aud
 		content|expand/jburn1.aud
diff --git a/mods/ts/mod.yaml b/mods/ts/mod.yaml
index ce81176a70..37e484d5a2 100644
--- a/mods/ts/mod.yaml
+++ b/mods/ts/mod.yaml
@@ -8,7 +8,7 @@ Metadata:
 PackageFormats: Mix
 
 FileSystem: ContentInstallerFileSystem
-	Packages:
+	SystemPackages:
 		^EngineDir
 		$ts: ts
 		^EngineDir|mods/common: common
@@ -38,6 +38,7 @@ FileSystem: ContentInstallerFileSystem
 		content|firestorm/e01vox02.mix
 		content|firestorm/ecache01.mix
 		~content|firestorm/scores01.mix
+		# Below are mod-provided (system) packages that need to be loaded after the content packages so they can override content assets.
 		ts|bits
 	ContentInstallerMod: ts-content