diff --git a/backend/src/plugins/Tags/TagsPlugin.ts b/backend/src/plugins/Tags/TagsPlugin.ts
index f6aa89e1..a73b4a42 100644
--- a/backend/src/plugins/Tags/TagsPlugin.ts
+++ b/backend/src/plugins/Tags/TagsPlugin.ts
@@ -203,7 +203,7 @@ export const TagsPlugin = zeppelinGuildPlugin<TagsPluginType>()("tags", {
           return "";
         }
 
-        if (input.match(/^<(?:@(?:!|&)?|#)\d+>$/)) {
+        if (input.match(/^<(?:@[!&]?|#)\d+>$/)) {
           return input;
         }
 
@@ -217,6 +217,14 @@ export const TagsPlugin = zeppelinGuildPlugin<TagsPluginType>()("tags", {
 
         return "";
       },
+
+      isMention: input => {
+        if (typeof input !== "string") {
+          return false;
+        }
+
+        return /^<(?:@[!&]?|#)\d+>$/.test(input);
+      },
     };
 
     for (const [name, fn] of Object.entries(state.tagFunctions)) {
diff --git a/backend/src/plugins/Tags/util/renderTagBody.ts b/backend/src/plugins/Tags/util/renderTagBody.ts
index dfde7a71..735455dc 100644
--- a/backend/src/plugins/Tags/util/renderTagBody.ts
+++ b/backend/src/plugins/Tags/util/renderTagBody.ts
@@ -25,6 +25,11 @@ export async function renderTagBody(
       if (typeof name !== "string") return;
       dynamicVars[name] = val;
     },
+    setr(name, val) {
+      if (typeof name !== "string") return "";
+      dynamicVars[name] = val;
+      return val;
+    },
     get(name) {
       return dynamicVars[name] == null ? "" : dynamicVars[name];
     },
diff --git a/backend/src/templateFormatter.ts b/backend/src/templateFormatter.ts
index 1963c816..e3575301 100644
--- a/backend/src/templateFormatter.ts
+++ b/backend/src/templateFormatter.ts
@@ -308,6 +308,18 @@ const baseValues = {
     if (end != null && isNaN(end)) return "";
     return arg1.slice(parseInt(start, 10), end && parseInt(end, 10));
   },
+  lower(arg) {
+    if (typeof arg !== "string") return arg;
+    return arg.toLowerCase();
+  },
+  upper(arg) {
+    if (typeof arg !== "string") return arg;
+    return arg.toUpperCase();
+  },
+  upperFirst(arg) {
+    if (typeof arg !== "string") return arg;
+    return arg.charAt(0).toUpperCase() + arg.slice(1);
+  },
   rand(from, to, seed = null) {
     if (isNaN(from)) return 0;