diff --git a/SabreTools.Library/DatFiles/DatFile.cs b/SabreTools.Library/DatFiles/DatFile.cs
index 207a1604..dfc2d643 100644
--- a/SabreTools.Library/DatFiles/DatFile.cs
+++ b/SabreTools.Library/DatFiles/DatFile.cs
@@ -1563,7 +1563,6 @@ namespace SabreTools.Library.DatFiles
 		/// <param name="inputPaths">Names of the input files and/or folders</param>
 		/// <param name="basePaths">Names of base files and/or folders</param>
 		/// <param name="outDir">Optional param for output directory</param>
-		/// <param name="merge">True if input files should be merged into a single file, false otherwise</param>
 		/// <param name="updateMode">Non-zero flag for diffing mode, zero otherwise</param>
 		/// <param name="inplace">True if the output files should overwrite their inputs, false otherwise</param>
 		/// <param name="skip">True if the first cascaded diff file should be skipped on output, false otherwise</param>
@@ -1576,64 +1575,62 @@ namespace SabreTools.Library.DatFiles
 		/// <param name="trim">True if we are supposed to trim names to NTFS length, false otherwise</param>
 		/// <param name="single">True if all games should be replaced by '!', false otherwise</param>
 		/// <param name="root">String representing root directory to compare against for length calculation</param>
-		public void DetermineUpdateType(List<string> inputPaths, List<string> basePaths, string outDir, bool merge, UpdateMode updateMode, bool inplace, bool skip,
+		public void DetermineUpdateType(List<string> inputPaths, List<string> basePaths, string outDir, UpdateMode updateMode, bool inplace, bool skip,
 			bool bare, bool clean, bool remUnicode, bool descAsName, Filter filter, SplitType splitType, bool trim, bool single, string root)
 		{
-			// If we're in merging or diffing mode, use the full list of inputs
-			if (merge || (updateMode != UpdateMode.None
-				&& (updateMode & UpdateMode.DiffAgainst) == 0)
-				&& (updateMode & UpdateMode.BaseReplace) == 0
-				&& (updateMode & UpdateMode.ReverseBaseReplace) == 0)
+			// If we're in standard update mode, run through all of the inputs
+			if (updateMode == UpdateMode.None)
+			{
+				Update(inputPaths, outDir, inplace, clean, remUnicode, descAsName, filter, splitType, trim, single, root);
+			}
+			// Otherwise, we're in one of the special modes
+			else
 			{
 				// Make sure there are no folders in inputs
 				List<string> newInputFileNames = Utilities.GetOnlyFilesFromInputs(inputPaths, appendparent: true);
 
-				// Reverse if we have to
+				// Reverse if we're in a required mode
 				if ((updateMode & UpdateMode.DiffReverseCascade) != 0)
 				{
 					newInputFileNames.Reverse();
 				}
 
-				// Create a dictionary of all ROMs from the input DATs
+				// Populate the combined data and get the headers
 				List<DatFile> datHeaders = PopulateUserData(newInputFileNames, inplace, clean,
-					remUnicode, descAsName, outDir, filter, splitType, trim, single, root);
+					   remUnicode, descAsName, outDir, filter, splitType, trim, single, root);
 
-				// Modify the Dictionary if necessary and output the results
-				if (updateMode != 0 && updateMode < UpdateMode.DiffCascade)
-				{
-					DiffNoCascade(updateMode, outDir, newInputFileNames);
-				}
-				// If we're in cascade and diff, output only cascaded diffs
-				else if (updateMode != 0 && updateMode >= UpdateMode.DiffCascade)
-				{
-					DiffCascade(outDir, inplace, newInputFileNames, datHeaders, skip);
-				}
-				// Output all entries with user-defined merge
-				else
+				// If we're in merging mode
+				if ((updateMode & UpdateMode.Merge) != 0)
 				{
 					MergeNoDiff(outDir, newInputFileNames, datHeaders);
 				}
+				// If we have one of the standard diffing modes
+				else if ((updateMode & UpdateMode.DiffDupesOnly) != 0
+					|| (updateMode & UpdateMode.DiffNoDupesOnly) != 0
+					|| (updateMode & UpdateMode.DiffIndividualsOnly) != 0)
+				{
+					DiffNoCascade(updateMode, outDir, newInputFileNames);
+				}
+				// If we have one of the cascaded diffing modes
+				else if ((updateMode & UpdateMode.DiffCascade) != 0
+					|| (updateMode & UpdateMode.DiffReverseCascade) != 0)
+				{
+					DiffCascade(outDir, inplace, newInputFileNames, datHeaders, skip);
+				}
+				// If we have diff against mode
+				else if ((updateMode & UpdateMode.DiffAgainst) != 0)
+				{
+					DiffAgainst(inputPaths, basePaths, outDir, inplace, clean, remUnicode, descAsName, filter, splitType, trim, single, root);
+				}
+				// If we have one of the base replacement modes
+				else if ((updateMode & UpdateMode.BaseReplace) != 0
+					|| (updateMode & UpdateMode.ReverseBaseReplace) != 0)
+				{
+					bool brrev = (updateMode & UpdateMode.ReverseBaseReplace) != 0;
+					BaseReplace(inputPaths, basePaths, outDir, inplace, clean, remUnicode, descAsName, filter, splitType, trim, single, root, brrev);
+				}
 			}
-			// If we're in "diff against" mode, we treat the inputs differently
-			else if ((updateMode & UpdateMode.DiffAgainst) != 0)
-			{
-				DiffAgainst(inputPaths, basePaths, outDir, inplace, clean, remUnicode, descAsName, filter, splitType, trim, single, root);
-			}
-			// If we're in "base replacement" mode, we treat the inputs differently
-			else if ((updateMode & UpdateMode.BaseReplace) != 0)
-			{
-				BaseReplace(inputPaths, basePaths, outDir, inplace, clean, remUnicode, descAsName, filter, splitType, trim, single, root, false);
-			}
-			// If we're in "reverse base replacement" mode, we treat the inputs differently
-			else if ((updateMode & UpdateMode.ReverseBaseReplace) != 0)
-			{
-				BaseReplace(inputPaths, basePaths, outDir, inplace, clean, remUnicode, descAsName, filter, splitType, trim, single, root, true);
-			}
-			// Otherwise, loop through all of the inputs individually
-			else
-			{
-				Update(inputPaths, outDir, inplace, clean, remUnicode, descAsName, filter, splitType, trim, single, root);
-			}
+
 			return;
 		}
 
diff --git a/SabreTools.Library/Data/Flags.cs b/SabreTools.Library/Data/Flags.cs
index 6c851e4b..8ad200df 100644
--- a/SabreTools.Library/Data/Flags.cs
+++ b/SabreTools.Library/Data/Flags.cs
@@ -293,7 +293,8 @@ namespace SabreTools.Library.Data
 		DiffAgainst = DiffReverseCascade << 1,
 
 		// Special update modes
-		BaseReplace = DiffAgainst << 1,
+		Merge = DiffAgainst << 1,
+		BaseReplace = Merge << 1,
 		ReverseBaseReplace = BaseReplace << 1,
 	}
 
diff --git a/SabreTools/SabreTools.Inits.cs b/SabreTools/SabreTools.Inits.cs
index 340beac7..4cab77df 100644
--- a/SabreTools/SabreTools.Inits.cs
+++ b/SabreTools/SabreTools.Inits.cs
@@ -300,8 +300,7 @@ namespace SabreTools
 		/// <param name="datprefix">Add the dat name as a directory prefix</param>
 		/// <param name="romba">Output files in romba format</param>
 		/// /* Merging and Diffing info */
-		/// <param name="merge">True if input files should be merged into a single file, false otherwise</param>
-		/// <param name="diffMode">Non-zero flag for diffing mode, zero otherwise</param>
+		/// <param name="updateMode">Non-zero flag for diffing mode, zero otherwise</param>
 		/// <param name="inplace">True if the cascade-diffed files should overwrite their inputs, false otherwise</param>
 		/// <param name="skip">True if the first cascaded diff file should be skipped on output, false otherwise</param>
 		/// <param name="bare">True if the date should not be appended to the default name, false otherwise [OBSOLETE]</param>
@@ -357,8 +356,7 @@ namespace SabreTools
 			bool romba,
 
 			/* Merging and Diffing info */
-			bool merge,
-			UpdateMode diffMode,
+			UpdateMode updateMode,
 			bool inplace,
 			bool skip,
 			bool bare,
@@ -389,8 +387,8 @@ namespace SabreTools
 			addext = (addext == "" || addext.StartsWith(".") ? addext : "." + addext);
 			repext = (repext == "" || repext.StartsWith(".") ? repext : "." + repext);
 
-			// If we're in merge or diff mode and the names aren't set, set defaults
-			if (merge || diffMode != 0)
+			// If we're in a special update mode and the names aren't set, set defaults
+			if (updateMode != 0)
 			{
 				// Get the values that will be used
 				if (date == "")
@@ -399,17 +397,17 @@ namespace SabreTools
 				}
 				if (name == "")
 				{
-					name = (diffMode != 0 ? "DiffDAT" : "MergeDAT") + (superdat ? "-SuperDAT" : "") + (dedup != DedupeType.None ? "-deduped" : "");
+					name = (updateMode != 0 ? "DiffDAT" : "MergeDAT") + (superdat ? "-SuperDAT" : "") + (dedup != DedupeType.None ? "-deduped" : "");
 				}
 				if (description == "")
 				{
-					description = (diffMode != 0 ? "DiffDAT" : "MergeDAT") + (superdat ? "-SuperDAT" : "") + (dedup != DedupeType.None ? " - deduped" : "");
+					description = (updateMode != 0 ? "DiffDAT" : "MergeDAT") + (superdat ? "-SuperDAT" : "") + (dedup != DedupeType.None ? " - deduped" : "");
 					if (!bare)
 					{
 						description += " (" + date + ")";
 					}
 				}
-				if (category == "" && diffMode != 0)
+				if (category == "" && updateMode != 0)
 				{
 					category = "DiffDAT";
 				}
@@ -456,7 +454,7 @@ namespace SabreTools
 				Romba = romba,
 			};
 			
-			userInputDat.DetermineUpdateType(inputPaths, basePaths, outDir, merge, diffMode, inplace, skip, bare, clean,
+			userInputDat.DetermineUpdateType(inputPaths, basePaths, outDir, updateMode, inplace, skip, bare, clean,
 				remUnicode, descAsName, filter, splitType, trim, single, root);
 		}
 
diff --git a/SabreTools/SabreTools.cs b/SabreTools/SabreTools.cs
index 4c5d397d..668b774f 100644
--- a/SabreTools/SabreTools.cs
+++ b/SabreTools/SabreTools.cs
@@ -98,7 +98,6 @@ namespace SabreTools
 				hashOnly = false,
 				inplace = false,
 				inverse = false,
-				merge = false,
 				nostore = false,
 				quickScan = false,
 				quotes = false,
@@ -398,7 +397,7 @@ namespace SabreTools
 						break;
 					case "-m":
 					case "--merge":
-						merge = true;
+						updateMode |= UpdateMode.Merge;
 						break;
 					case "-nc":
 					case "--nodump-col":
@@ -1302,7 +1301,7 @@ namespace SabreTools
 			{
 				InitUpdate(inputs, basePaths, filename, name, description, rootdir, category, version, date, author, email, homepage, url, comment, header,
 					superdat, forcemerge, forcend, forcepack, excludeOf, sceneDateStrip, datFormat, usegame, prefix, postfix, quotes, repext, addext, remext,
-					datPrefix, romba, merge, updateMode, inplace, skip, removeDateFromAutomaticName, filter, splitType, trim, single, root, outDir,
+					datPrefix, romba, updateMode, inplace, skip, removeDateFromAutomaticName, filter, splitType, trim, single, root, outDir,
 					cleanGameNames, removeUnicode, descAsName, dedup, stripHash);
 			}