docs(): mention implicit usage of

Author: tbosch

src/ng/sce.js

@@ -519,7 +519,7 @@ function $SceDelegateProvider() {
  *
  * | Context             | Notes          |
  * |---------------------|----------------|
- * | `$sce.HTML`         | For HTML that's safe to source into the application.  The {@link ng.directive:ngBindHtml ngBindHtml} directive uses this context for bindings. |
+ * | `$sce.HTML`         | For HTML that's safe to source into the application.  The {@link ng.directive:ngBindHtml ngBindHtml} directive uses this context for bindings. If an unsafe value is encountered and the {@link ngSanitize $sanitize} module is present this will sanitize the value instead of throwing an error. |
  * | `$sce.CSS`          | For CSS that's safe to source into the application.  Currently unused.  Feel free to use it in your own directives. |
  * | `$sce.URL`          | For URLs that are safe to follow as links.  Currently unused (`<a href=` and `<img src=` sanitize their urls and don't constitute an SCE context. |
  * | `$sce.RESOURCE_URL` | For URLs that are not only safe to follow as links, but whose contents are also safe to include in your application.  Examples include `ng-include`, `src` / `ngSrc` bindings for tags other than `IMG` (e.g. `IFRAME`, `OBJECT`, etc.)  <br><br>Note that `$sce.RESOURCE_URL` makes a stronger statement about the URL than `$sce.URL` does and therefore contexts requiring values trusted for `$sce.RESOURCE_URL` can be used anywhere that values trusted for `$sce.URL` are required. |