This exemption is a bit fluid because it defers to the html specification. In essence, anything the html specification says a script element can reference we allow without the need for a manifest fallback.
Looking at the html spec, it says:
The second core attribute is the src attribute. It must only be specified for classic scripts and JavaScript module scripts, and denotes that instead of using the element's child text content as the script content, the script will be fetched from the specified URL.
That seems to only allow JS, JSON, CSS and WASM, but I could be misreading it.
This exemption is a bit fluid because it defers to the html specification. In essence, anything the html specification says a script element can reference we allow without the need for a manifest fallback.
Looking at the html spec, it says:
That seems to only allow JS, JSON, CSS and WASM, but I could be misreading it.