diff --git a/tools/api-builder/angular.io-package/tag-defs/Annotation.js b/tools/api-builder/angular.io-package/tag-defs/Annotation.js
new file mode 100644
index 0000000000..223195a9d7
--- /dev/null
+++ b/tools/api-builder/angular.io-package/tag-defs/Annotation.js
@@ -0,0 +1,4 @@
+// A ts2dart compiler annotation that can be ignored in API docs.
+module.exports = function() {
+  return { name: 'Annotation', ignore: true };
+};
diff --git a/tools/api-builder/angular.io-package/tag-defs/index.js b/tools/api-builder/angular.io-package/tag-defs/index.js
index 782a09189e..bbc9f5d167 100644
--- a/tools/api-builder/angular.io-package/tag-defs/index.js
+++ b/tools/api-builder/angular.io-package/tag-defs/index.js
@@ -1,9 +1,11 @@
 module.exports = [
+  require('./Annotation'),
   require('./deprecated'),
   require('./howToUse'),
   require('./whatItDoes'),
   require('./internal'),
   require('./stable'),
+  require('./ts2dart_const'),
   require('./experimental'),
   require('./docsNotRequired'),
   require('./security'),
diff --git a/tools/api-builder/angular.io-package/tag-defs/ts2dart_const.js b/tools/api-builder/angular.io-package/tag-defs/ts2dart_const.js
new file mode 100644
index 0000000000..dc2c3fa401
--- /dev/null
+++ b/tools/api-builder/angular.io-package/tag-defs/ts2dart_const.js
@@ -0,0 +1,4 @@
+// A ts2dart compiler annotation that can be ignored in API docs.
+module.exports = function() {
+  return { name: 'ts2dart_const', ignore: true };
+};