diff --git a/UserTalkErasedSectionsDetector.js b/UserTalkErasedSectionsDetector.js
new file mode 100644
index 0000000..3706436
--- /dev/null
+++ b/UserTalkErasedSectionsDetector.js
@@ -0,0 +1,168 @@
+// <nowiki>
+
+/*
+A user script that alerts you with a yellow banner at the top of a User Talk page if a user has deleted content from more than 15 of the last 500 diffs.
+
+Useful for detecting if a WP:PERM applicant is whitewashing their User Talk page by removing warnings without archiving them.
+*/
+
+class ErasedSectionsDetector {
+	/** @type {object} */
+	mw;
+	/** @type {object} */
+	$;
+	/** @type {object} */
+	revisions;
+
+	constructor( mw, $ ) {
+		this.mw = mw;
+		this.$ = $;
+	}
+
+	async execute() {
+		if ( ! this.shouldRunOnThisPage() ) {
+			return;
+		}
+		let title = this.mw.config.get( 'wgPageName' ).replace(/_/g, ' ');
+		this.revisions = await this.getRevisions( title );
+		let totalRevisionCount = this.revisions.length;
+		this.addDiffsToRevisions();
+		this.filterForRevisionsByThisEditorOnly();
+		this.filterForNegativeDiffs();
+		this.filterOutArchiving();
+		this.addASpaceToBlankEditSummaries();
+		let negativeDiffCount = this.revisions.length;
+		if ( negativeDiffCount > 15 ) {
+			this.addHtml( negativeDiffCount, totalRevisionCount );
+		}
+		this.listenForShowDiffsClick();
+	}
+
+	/**
+	 * Add a space to blank edit summaries. This is so the hyperlink can be clicked.
+	 */
+	addASpaceToBlankEditSummaries() {
+		this.revisions = this.revisions.map( function( revision ) {
+			if ( revision.comment === '' ) {
+				revision.comment = '[no edit summary]';
+			}
+			return revision;
+		} );
+	}
+
+	listenForShowDiffsClick() {
+		this.$( '#ErasedSectionsDetector-SeeDiffs' ).on( 'click', function() {
+			this.$( '#ErasedSectionsDetector-Diffs' ).toggle();
+		}.bind(this) );
+	}
+
+	addHtml( negativeDiffCount, totalRevisionCount ) {
+		let html = `
+			<div class="ErasedSectionsDetector">
+				<div style="background-color: yellow">
+					<span style="font-weight:bold">Warning:</span> This user has removed content from this page (probably without archiving it) in ${ negativeDiffCount } of the last ${ totalRevisionCount } revisions. <a id="ErasedSectionsDetector-SeeDiffs">Click here</a> to see diffs.
+				</div>
+				
+				<div id="ErasedSectionsDetector-Diffs" style="border: 1px solid black; font-size: 80%; display: none;">
+					<ul>
+		`;
+
+		for ( let revision of this.revisions ) {
+			html += `
+						<li>
+							<a href="w/index.php?title=${ encodeURIComponent( this.mw.config.get( 'wgPageName' ) ) }&diff=prev&oldid=${ revision.revid }">
+								${ revision.comment }
+							</a>
+						</li>
+			`;
+		}
+
+		html += `
+					</ul>
+				</div>
+			</div>
+		`;
+
+		this.$( '#contentSub2' ).after( html );
+	}
+
+	filterForNegativeDiffs() {
+		this.revisions = this.revisions.filter( ( revision ) => revision.diff < 0 );
+	}
+
+	filterForRevisionsByThisEditorOnly() {
+		let needle = this.mw.config.get( 'wgTitle' );
+		this.revisions = this.revisions.filter( ( revision ) => revision.user === needle );
+	}
+
+	filterOutArchiving() {
+		this.revisions = this.revisions.filter( ( revision ) => ! revision.comment.includes( 'OneClickArchiver' ) );
+		this.revisions = this.revisions.filter( ( revision ) => ! revision.comment.toLowerCase().includes( 'archiv' ) ); // archiving, archive
+	}
+
+	/**
+	 * Given the Action API output of query revisions as a JavaScript object, add to this object a field called "diff" that is the difference +/- in size of that diff compared to the next oldest diff.
+	 */
+	addDiffsToRevisions() {
+		let len = this.revisions.length;
+		let lastRevisionSize = this.revisions[len - 1].size;
+		// iterate backwards. need to store the older revision's size in a buffer to compute a diff.
+		for ( let i = (len - 2); i >= 0; i-- ) {
+			let thisRevisionSize = this.revisions[i].size;
+			this.revisions[i].diff = thisRevisionSize - lastRevisionSize;
+			lastRevisionSize = thisRevisionSize;
+		}
+	}
+
+	async getRevisions( title ) {
+		let api = new mw.Api();
+		let response = await api.get( {
+			action: "query",
+			format: "json",
+			prop: "revisions",
+			titles: title,
+			formatversion: "2",
+			rvprop: "comment|size|user|ids",
+			rvslots: "",
+			rvlimit: "500", // get 500 revisions
+			rvdir: "older" // get newest revisions (enumerate towards older entries)
+		} );
+		return response.query.pages[0].revisions;
+	}
+
+	shouldRunOnThisPage() {
+		let isViewing = this.mw.config.get('wgAction') === 'view';
+		if ( ! isViewing ) {
+			return false;
+		}
+
+		let isDiff = this.mw.config.get('wgDiffNewId');
+		if ( isDiff ) {
+			return false;
+		}
+
+		let isDeletedPage = ! this.mw.config.get('wgCurRevisionId') ;
+		if ( isDeletedPage ) {
+			return false;
+		}
+
+		let namespace = this.mw.config.get('wgNamespaceNumber');
+		let isUserTalkNamespace = [3].includes( namespace );
+		if ( ! isUserTalkNamespace ) {
+			return false;
+		}
+
+		let isSubPage = this.mw.config.get( 'wgPageName' ).includes( '/' );
+		if ( isSubPage ) {
+			return;
+		}
+
+		return true;
+	}
+}
+
+$(async function() {
+	await ( new ErasedSectionsDetector( mw, $ ) ).execute();
+});
+
+// </nowiki>