The `$sanitize` service [tells me that](http://docs.angularjs.org/api/ngSanitize.$sanitize)

> 
> All safe tokens (from a whitelist) are then serialized back to
>  properly escaped html string.
> 
> 
> 

I want to only display an even smaller subset of HTML (viz `em`,`p`,`a`, and `strong`). Is there a way to easily modify the `$service` whitelist without having to modify the core JavaScript?