diff --git a/wp-includes/deprecated.php b/wp-includes/deprecated.php
index 5823ee8296..985fa4e0ff 100644
--- a/wp-includes/deprecated.php
+++ b/wp-includes/deprecated.php
@@ -3430,3 +3430,18 @@ function wp_style_loader_src() {}
 function default_topic_count_text( $count ) {
 	return $count;
 }
+
+/**
+ * Formerly used to escape strings before INSERTing into the DB. Hasn't performed this function for many, many years.
+ *
+ * @since 0.71
+ * @deprecated 3.9.0
+ * @deprecated Original intent was to add slashes to POSTed data, use $wpdb::prepare() instead
+ *
+ * @param string $content The text to format.
+ * @return string The very same text.
+ */
+function format_to_post( $content ) {
+	_deprecated_function( __FUNCTION__, '3.9' );
+	return $content;
+}
diff --git a/wp-includes/formatting.php b/wp-includes/formatting.php
index 9edea6a704..f4c762bc86 100644
--- a/wp-includes/formatting.php
+++ b/wp-includes/formatting.php
@@ -1424,26 +1424,6 @@ function format_to_edit( $content, $richedit = false ) {
 	return $content;
 }
 
-/**
- * Holder for the 'format_to_post' filter.
- *
- * @since 0.71
- *
- * @param string $content The text to pass through the filter.
- * @return string Text returned from the 'format_to_post' filter.
- */
-function format_to_post($content) {
-	/**
-	 * Filter the string returned by format_to_post().
-	 *
-	 * @since 1.2.0
-	 *
-	 * @param string $content The string to format.
-	 */
-	$content = apply_filters( 'format_to_post', $content );
-	return $content;
-}
-
 /**
  * Add leading zeros when necessary.
  *