diff --git a/types/lib/utils/templatize.d.ts b/types/lib/utils/templatize.d.ts
index c31fa6e495..0329db987c 100644
--- a/types/lib/utils/templatize.d.ts
+++ b/types/lib/utils/templatize.d.ts
@@ -129,6 +129,15 @@ declare namespace Polymer {
      *   from `instance.parentModel` in cases where template instance nesting
      *   causes an inner model to shadow an outer model.
      *
+     * When `options.forwardHostProp` is declared as an option, any properties
+     * referenced in the template will be automatically forwarded from the host of
+     * the `<template>` to instances, with the exception of any properties listed in
+     * the `options.instanceProps` object.  `instanceProps` are assumed to be
+     * managed by the owner of the instances, either passed into the constructor
+     * or set after the fact.  Note, any properties passed into the constructor will
+     * always be set to the instance (regardless of whether they would normally
+     * be forwarded from the host).
+     *
      * Note that the class returned from `templatize` is generated only once
      * for a given `<template>` using `options` from the first call for that
      * template, and the cached class is returned for all subsequent calls to