diff --git a/core/modules/commands/save.js b/core/modules/commands/save.js
index 9769cec69..3cb7ef08c 100644
--- a/core/modules/commands/save.js
+++ b/core/modules/commands/save.js
@@ -43,7 +43,9 @@ Saves individual tiddlers in their raw text or binary format to the specified fi
 						directory: path.resolve(self.commander.outputPath),
 						pathFilters: [filenameFilter],
 						wiki: wiki,
-						fileInfo: {}
+						fileInfo: {
+							overwrite: true
+						}
 					});
 					if(self.commander.verbose) {
 						console.log("Saving \"" + title + "\" to \"" + fileInfo.filepath + "\"");
diff --git a/core/modules/server/server.js b/core/modules/server/server.js
index ce40bb3ae..a700fb146 100644
--- a/core/modules/server/server.js
+++ b/core/modules/server/server.js
@@ -140,6 +140,11 @@ function sendResponse(request,response,statusCode,headers,data,encoding) {
 				return;
 			}
 		}
+	} else {
+		// RFC 7231, 6.1. Overview of Status Codes:
+		// Browser clients may cache 200, 203, 204, 206, 300, 301, 
+		// 404, 405, 410, 414, and 501 unless given explicit cache controls
+		headers["Cache-Control"] = headers["Cache-Control"] || "no-store";
 	}
 	/*
 	If the gzip=yes is set, check if the user agent permits compression. If so,
diff --git a/core/modules/utils/filesystem.js b/core/modules/utils/filesystem.js
index 1ba34323e..5319e0481 100644
--- a/core/modules/utils/filesystem.js
+++ b/core/modules/utils/filesystem.js
@@ -316,11 +316,13 @@ Options include:
 	pathFilters: optional array of filters to be used to generate the base path
 	wiki: optional wiki for evaluating the pathFilters
 	fileInfo: an existing fileInfo object to check against
+	fileInfo.overwrite: if true, turns off filename clash numbers (defaults to false)
 */
 exports.generateTiddlerFilepath = function(title,options) {
 	var directory = options.directory || "",
 		extension = options.extension || "",
 		originalpath = (options.fileInfo && options.fileInfo.originalpath) ? options.fileInfo.originalpath : "",
+		overwrite = options.fileInfo && options.fileInfo.overwrite || false,
 		filepath;
 	// Check if any of the pathFilters applies
 	if(options.pathFilters && options.wiki) {
@@ -381,19 +383,20 @@ exports.generateTiddlerFilepath = function(title,options) {
 			filepath += char.charCodeAt(0).toString();
 		});
 	}
-	// Add a uniquifier if the file already exists
-	var fullPath, oldPath = (options.fileInfo) ? options.fileInfo.filepath : undefined,
+	// Add a uniquifier if the file already exists (default)
+	var fullPath = path.resolve(directory, filepath + extension);
+	if (!overwrite) {
+		var oldPath = (options.fileInfo) ? options.fileInfo.filepath : undefined,
 		count = 0;
-	do {
-		fullPath = path.resolve(directory,filepath + (count ? "_" + count : "") + extension);
-		if(oldPath && oldPath == fullPath) {
-			break;
-		}
-		count++;
-	} while(fs.existsSync(fullPath));
+		do {
+			fullPath = path.resolve(directory,filepath + (count ? "_" + count : "") + extension);
+			if(oldPath && oldPath == fullPath) break;
+			count++;
+		} while(fs.existsSync(fullPath));
+	}
 	// If the last write failed with an error, or if path does not start with:
 	//	the resolved options.directory, the resolved wikiPath directory, the wikiTiddlersPath directory, 
-	//	or the 'originalpath' directory, then $tw.utils.encodeURIComponentExtended() and resolve to tiddler directory.
+	//	or the 'originalpath' directory, then $tw.utils.encodeURIComponentExtended() and resolve to options.directory.
 	var writePath = $tw.hooks.invokeHook("th-make-tiddler-path",fullPath,fullPath),
 		encode = (options.fileInfo || {writeError: false}).writeError == true;
 	if(!encode) {
diff --git a/core/modules/widgets/action-deletefield.js b/core/modules/widgets/action-deletefield.js
index 54068471e..00f06562d 100644
--- a/core/modules/widgets/action-deletefield.js
+++ b/core/modules/widgets/action-deletefield.js
@@ -37,6 +37,7 @@ Compute the internal state of the widget
 DeleteFieldWidget.prototype.execute = function() {
 	this.actionTiddler = this.getAttribute("$tiddler",this.getVariable("currentTiddler"));
 	this.actionField = this.getAttribute("$field",null);
+	this.actionTimestamp = this.getAttribute("$timestamp","yes") === "yes";
 };
 
 /*
@@ -69,11 +70,15 @@ DeleteFieldWidget.prototype.invokeAction = function(triggeringWidget,event) {
 		$tw.utils.each(this.attributes,function(attribute,name) {
 			if(name.charAt(0) !== "$" && name !== "title") {
 				removeFields[name] = undefined;
-				hasChanged = true;
+				if(name in tiddler.fields) {
+					hasChanged = true;
+				}
 			}
 		});
 		if(hasChanged) {
-			this.wiki.addTiddler(new $tw.Tiddler(this.wiki.getCreationFields(),tiddler,removeFields,this.wiki.getModificationFields()));
+			var creationFields = this.actionTimestamp ? this.wiki.getCreationFields() : {};
+			var modificationFields = this.actionTimestamp ? this.wiki.getModificationFields() : {};
+			this.wiki.addTiddler(new $tw.Tiddler(creationFields,tiddler,removeFields,modificationFields));
 		}
 	}
 	return true; // Action was invoked
diff --git a/core/templates/external-js/save-all-external-js.tid b/core/templates/external-js/save-all-external-js.tid
index ff5bbc851..1f4908878 100644
--- a/core/templates/external-js/save-all-external-js.tid
+++ b/core/templates/external-js/save-all-external-js.tid
@@ -3,7 +3,7 @@ title: $:/core/save/all-external-js
 \whitespace trim
 \import [subfilter{$:/core/config/GlobalImportFilter}]
 \define saveTiddlerFilter()
-[is[tiddler]] -[prefix[$:/state/popup/]] -[prefix[$:/temp/]] -[prefix[$:/HistoryList]] -[status[pending]plugin-type[import]] -[[$:/core]] -[[$:/boot/boot.css]] -[type[application/javascript]library[yes]] -[[$:/boot/boot.js]] -[[$:/boot/bootprefix.js]] +[sort[title]] $(publishFilter)$
+[is[tiddler]] -[prefix[$:/state/popup/]] -[prefix[$:/temp/]] -[prefix[$:/HistoryList]] -[status[pending]plugin-type[import]] -[[$:/core]] -[[$:/boot/boot.css]] -[is[system]type[application/javascript]library[yes]] -[[$:/boot/boot.js]] -[[$:/boot/bootprefix.js]] +[sort[title]] $(publishFilter)$
 \end
 
 <!-- Important: core library is provided by serving URI encoded $:/core/templates/tiddlywiki5.js -->
diff --git a/core/templates/external-js/save-offline-external-js.tid b/core/templates/external-js/save-offline-external-js.tid
index 564a34948..70cb8bbc0 100644
--- a/core/templates/external-js/save-offline-external-js.tid
+++ b/core/templates/external-js/save-offline-external-js.tid
@@ -3,7 +3,7 @@ title: $:/core/save/offline-external-js
 \whitespace trim
 \import [subfilter{$:/core/config/GlobalImportFilter}]
 \define saveTiddlerFilter()
-[is[tiddler]] -[prefix[$:/state/popup/]] -[prefix[$:/temp/]] -[prefix[$:/HistoryList]] -[status[pending]plugin-type[import]] -[[$:/core]] -[[$:/plugins/tiddlywiki/filesystem]] -[[$:/plugins/tiddlywiki/tiddlyweb]] -[[$:/boot/boot.css]] -[type[application/javascript]library[yes]] -[[$:/boot/boot.js]] -[[$:/boot/bootprefix.js]] +[sort[title]] $(publishFilter)$
+[is[tiddler]] -[prefix[$:/state/popup/]] -[prefix[$:/temp/]] -[prefix[$:/HistoryList]] -[status[pending]plugin-type[import]] -[[$:/core]] -[[$:/plugins/tiddlywiki/filesystem]] -[[$:/plugins/tiddlywiki/tiddlyweb]] -[[$:/boot/boot.css]] -[is[system]type[application/javascript]library[yes]] -[[$:/boot/boot.js]] -[[$:/boot/bootprefix.js]] +[sort[title]] $(publishFilter)$
 \end
 \define defaultCoreURL() tiddlywikicore-$(version)$.js
 <$let coreURL={{{ [[coreURL]is[variable]then<coreURL>else<defaultCoreURL>] }}}>
diff --git a/core/templates/save-all.tid b/core/templates/save-all.tid
index d7473ba5b..a316d1954 100644
--- a/core/templates/save-all.tid
+++ b/core/templates/save-all.tid
@@ -2,6 +2,6 @@ title: $:/core/save/all
 
 \import [subfilter{$:/core/config/GlobalImportFilter}]
 \define saveTiddlerFilter()
-[is[tiddler]] -[prefix[$:/state/popup/]] -[prefix[$:/temp/]] -[prefix[$:/HistoryList]] -[status[pending]plugin-type[import]] -[[$:/boot/boot.css]] -[type[application/javascript]library[yes]] -[[$:/boot/boot.js]] -[[$:/boot/bootprefix.js]] +[sort[title]] $(publishFilter)$
+[is[tiddler]] -[prefix[$:/state/popup/]] -[prefix[$:/temp/]] -[prefix[$:/HistoryList]] -[status[pending]plugin-type[import]] -[[$:/boot/boot.css]] -[is[system]type[application/javascript]library[yes]] -[[$:/boot/boot.js]] -[[$:/boot/bootprefix.js]] +[sort[title]] $(publishFilter)$
 \end
 {{$:/core/templates/tiddlywiki5.html}}
diff --git a/core/templates/save-empty.tid b/core/templates/save-empty.tid
index 6f0da4822..0b1c33b59 100644
--- a/core/templates/save-empty.tid
+++ b/core/templates/save-empty.tid
@@ -1,6 +1,6 @@
 title: $:/core/save/empty
 
 \define saveTiddlerFilter()
-[is[system]] -[prefix[$:/state/popup/]] -[[$:/boot/boot.css]] -[type[application/javascript]library[yes]] -[[$:/boot/boot.js]] -[[$:/boot/bootprefix.js]] +[sort[title]]
+[is[system]] -[prefix[$:/state/popup/]] -[[$:/boot/boot.css]] -[is[system]type[application/javascript]library[yes]] -[[$:/boot/boot.js]] -[[$:/boot/bootprefix.js]] +[sort[title]]
 \end
 {{$:/core/templates/tiddlywiki5.html}}
diff --git a/core/templates/save-lazy-all.tid b/core/templates/save-lazy-all.tid
index a4b5cd6e9..da4353fba 100644
--- a/core/templates/save-lazy-all.tid
+++ b/core/templates/save-lazy-all.tid
@@ -1,7 +1,7 @@
 title: $:/core/save/lazy-all
 
 \define saveTiddlerFilter()
-[is[system]] -[prefix[$:/state/popup/]] -[[$:/HistoryList]] -[[$:/boot/boot.css]] -[type[application/javascript]library[yes]] -[[$:/boot/boot.js]] -[[$:/boot/bootprefix.js]] [is[tiddler]type[application/javascript]] +[sort[title]]
+[is[system]] -[prefix[$:/state/popup/]] -[[$:/HistoryList]] -[[$:/boot/boot.css]] -[is[system]type[application/javascript]library[yes]] -[[$:/boot/boot.js]] -[[$:/boot/bootprefix.js]] [is[tiddler]type[application/javascript]] +[sort[title]]
 \end
 \define skinnySaveTiddlerFilter()
 [!is[system]] -[type[application/javascript]]
diff --git a/core/templates/save-lazy-images.tid b/core/templates/save-lazy-images.tid
index 0a4a84295..b23b348f0 100644
--- a/core/templates/save-lazy-images.tid
+++ b/core/templates/save-lazy-images.tid
@@ -1,7 +1,7 @@
 title: $:/core/save/lazy-images
 
 \define saveTiddlerFilter()
-[is[tiddler]] -[prefix[$:/state/popup/]] -[[$:/HistoryList]] -[[$:/boot/boot.css]] -[type[application/javascript]library[yes]] -[[$:/boot/boot.js]] -[[$:/boot/bootprefix.js]] -[!is[system]is[image]] +[sort[title]] 
+[is[tiddler]] -[prefix[$:/state/popup/]] -[[$:/HistoryList]] -[[$:/boot/boot.css]] -[is[system]type[application/javascript]library[yes]] -[[$:/boot/boot.js]] -[[$:/boot/bootprefix.js]] -[!is[system]is[image]] +[sort[title]] 
 \end
 \define skinnySaveTiddlerFilter()
 [!is[system]is[image]]
diff --git a/editions/test/tiddlers/tests/test-action-deletefield.js b/editions/test/tiddlers/tests/test-action-deletefield.js
new file mode 100644
index 000000000..876f44d8e
--- /dev/null
+++ b/editions/test/tiddlers/tests/test-action-deletefield.js
@@ -0,0 +1,176 @@
+/*\
+title: test-action-deletefield.js
+type: application/javascript
+tags: [[$:/tags/test-spec]]
+
+Tests <$action-deletefield />.
+
+\*/
+(function(){
+
+/* jslint node: true, browser: true */
+/* eslint-env node, browser, jasmine */
+/* eslint no-mixed-spaces-and-tabs: ["error", "smart-tabs"]*/
+/* global $tw, require */
+"use strict";
+
+describe("<$action-deletefield /> tests", function() {
+
+const TEST_TIDDLER_TITLE = "TargetTiddler";
+const TEST_TIDDLER_MODIFIED = "20240313114828368";
+
+function setupWiki(condition, targetField, wikiOptions) {
+	// Create a wiki
+	var wiki = new $tw.Wiki({});
+	var tiddlers = [{
+		title: "Root",
+		text: "Some dummy content"
+	}];
+	var tiddler;
+	if(condition.targetTiddlerExists) {
+		var fields = {
+			title: TEST_TIDDLER_TITLE,
+		};
+		if(condition.modifiedFieldExists) {
+			fields.modified = TEST_TIDDLER_MODIFIED;
+		}
+		if(condition.targetFieldExists) {
+			fields[targetField] = "some text";
+		}
+		var tiddler = new $tw.Tiddler(fields);
+		tiddlers.push(tiddler);
+	}
+	wiki.addTiddlers(tiddlers);
+	wiki.addIndexersToWiki();
+	var widgetNode = wiki.makeTranscludeWidget("Root",{document: $tw.fakeDocument, parseAsInline: true});
+	var container = $tw.fakeDocument.createElement("div");
+	widgetNode.render(container,null);
+	return {
+		wiki: wiki,
+		widgetNode: widgetNode,
+		contaienr: container,
+		tiddler: tiddler,
+	};
+}
+
+function generateTestConditions() {
+	var conditions = [];
+
+	$tw.utils.each([true, false], function(tiddlerArgumentIsPresent) {
+		$tw.utils.each([true, false], function(targetTiddlerExists) {
+			$tw.utils.each([true, false], function(targetFieldExists) {
+				$tw.utils.each([true, false], function(fieldArgumentIsUsed) {
+					$tw.utils.each([true, false], function(modifiedFieldExists) {
+						$tw.utils.each(["", "yes", "no"], function(timestampArgument) {
+							conditions.push({
+								tiddlerArgumentIsPresent: tiddlerArgumentIsPresent,
+								targetTiddlerExists: targetTiddlerExists,
+								targetFieldExists: targetFieldExists,
+								fieldArgumentIsUsed: fieldArgumentIsUsed,
+								modifiedFieldExists: modifiedFieldExists,
+								timestampArgument: timestampArgument,
+							});
+						});
+					});
+				});
+			});
+		});
+	});
+
+	return conditions;
+}
+
+function generateActionWikitext(condition, targetField) {
+	var actionPieces = [
+		"<$action-deletefield",
+		(condition.tiddlerArgumentIsPresent ? "$tiddler='" + TEST_TIDDLER_TITLE + "'" : ""),
+		(condition.fieldArgumentIsUsed ? "$field='" + targetField + "'" : targetField),
+		(condition.timestampArgument !== "" ? "$timestamp='" + condition.timestampArgument + "'" : ""),
+		"/>",
+	];
+
+	return actionPieces.join(" ");
+}
+
+function generateTestContext(action, tiddler) {
+	var expectationContext = "action: " + action + "\ntiddler:\n\n";
+	if(tiddler) {
+		expectationContext += tiddler.getFieldStringBlock({exclude: ["text"]});
+		if(tiddler.text) {
+			expectationContext += "\n\n" + tiddler.text;
+		}
+		expectationContext += "\n\n";
+	} else {
+		expectationContext += "null";
+	}
+
+	return expectationContext;
+}
+
+it("should correctly delete fields", function() {
+	var fields = ['caption', 'description', 'text'];
+
+	var conditions = generateTestConditions();
+
+	$tw.utils.each(conditions, function(condition) {
+		$tw.utils.each(fields, function(field) {
+			var info = setupWiki(condition, field);
+			var originalTiddler = info.tiddler;
+
+			var invokeActions = function(actions) {
+				info.widgetNode.invokeActionString(actions,info.widgetNode,null,{
+					currentTiddler: TEST_TIDDLER_TITLE,
+				});
+			};
+
+			var action = generateActionWikitext(condition,field);
+
+			invokeActions(action);
+
+			var testContext = generateTestContext(action,originalTiddler);
+
+			var tiddler = info.wiki.getTiddler(TEST_TIDDLER_TITLE);
+			if(originalTiddler) {
+				// assert that the tiddler doesn't have the target field anymore
+				expect(tiddler.hasField(field)).withContext(testContext).toBeFalsy();
+
+				var targetFieldWasPresent = originalTiddler.hasField(field);
+				var updateTimestamps = condition.timestampArgument !== "no";
+
+				// "created" should exist if it did beforehand, or if the tiddler changed and we asked the widget to update timestamps
+				var createdFieldShouldExist = originalTiddler.hasField("created") || (targetFieldWasPresent && updateTimestamps);
+
+				// "created" should change only if it didn't exist beforehand and the tiddler changed and we asked the widget to update timestamps
+				var createdFieldShouldChange = !originalTiddler.hasField("created") && (targetFieldWasPresent && updateTimestamps);
+
+				// "modified" should exist if it did beforehand, or if the tiddler changed and we asked the widget to update timestamps
+				var modifiedFieldShouldExist = originalTiddler.hasField("modified") || (targetFieldWasPresent && updateTimestamps);
+
+				// "modified" should change if the tiddler changed and we asked the widget to update timestamps
+				var modifiedFieldShouldChange = targetFieldWasPresent && updateTimestamps;
+
+				expect(tiddler.hasField("created")).withContext(testContext).toBe(createdFieldShouldExist);
+				expect(tiddler.hasField("modified")).withContext(testContext).toBe(modifiedFieldShouldExist);
+
+				if(createdFieldShouldChange) {
+					expect(tiddler.fields.created).withContext(testContext).not.toEqual(originalTiddler.fields.created);
+				} else {
+					expect(tiddler.fields.created).withContext(testContext).toEqual(originalTiddler.fields.created);
+				}
+
+				if(modifiedFieldShouldChange) {
+					expect(tiddler.fields.modified).withContext(testContext).not.toEqual(originalTiddler.fields.modified);
+				} else {
+					expect(tiddler.fields.modified).withContext(testContext).toEqual(originalTiddler.fields.modified);
+				}
+			} else {
+				// assert that the tiddler didn't get created if it didn't exist already
+				expect(tiddler).withContext(testContext).toBeUndefined();
+			}
+		});
+	});
+});
+
+});
+
+})();
diff --git a/editions/tw5.com/tiddlers/widgets/ActionDeleteFieldWidget.tid b/editions/tw5.com/tiddlers/widgets/ActionDeleteFieldWidget.tid
index 2855804fd..5b797232b 100644
--- a/editions/tw5.com/tiddlers/widgets/ActionDeleteFieldWidget.tid
+++ b/editions/tw5.com/tiddlers/widgets/ActionDeleteFieldWidget.tid
@@ -16,6 +16,7 @@ The ''action-deletefield'' widget is invisible. Any content within it is ignored
 |!Attribute |!Description |
 |$tiddler |The title of the tiddler whose fields are to be modified (if not provided defaults to the [[current tiddler|Current Tiddler]]) |
 |$field |Optional name of a field to delete |
+|$timestamp |<<.from-version "5.3.4">> Specifies whether the timestamp(s) of the target tiddler will be updated (''modified'' and ''modifier'', plus ''created'' and ''creator'' for newly created tiddlers). Can be "yes" (the default) or "no" |
 |//{any attributes not starting with $}// |Each attribute name specifies a field to be deleted. The attribute value is ignored and need not be specified |
 
 ! Examples