Comment by asdfalsrgkj

How about:

- no scripts of any kind

- no cookies

- no forms

- all resources (e.g., styles, images) needed for display inlined

- a spacious minimum cap on data URI length

- elaborate the <a> tag a bit to allow a series of content addresses (hashes, IPFS, magnet URIs, etc.) for references

Basically, a "dead" subset of HTML suitable for distributing documents.