Internal referencing and internal only resources

[BigBlueHat]

Question related to the "bundling" spec draft: #98

Are there plans to include an internal referencing mechanism similar to MHTML's use of Content-ID or the TAG's previous Packaging on the Web's use of fragment identifiers?

For instance, book (et al) publishers are coming from EPUB where "everything" is built using internal references and internal-only resources. Additionally, there may be other use cases where "internal only" package contents might be needed and beneficial.

If that seems out of scope for this sort of bundling, though, no worries. Just wanted to check. 😃

We'll be exploring that need in the Publishing WG via w3c/pwpub#24

Thanks!
🎩