Comment by troupo

> It’s been implemented in Chromium for 4–6 years

It makes it a non-official Chrome-only non-standard

> Firefox’s position is positive (admittedly that was 2019), WebKit’s is neutral,

Positions don't make a spec

> but this one is not really like that—it’s just that the other two platforms are missing a couple of other pieces

It literally means that in the very literal sense of the word literal:

The "Status of this document" section states the following:

--- start quote ---

This document is a draft of a potential specification. It has no official standing of any kind and does not represent the support or consensus of any standards organization.

--- end quote ---

Which part of that tells you that "it's not like that"? It's not even on a standards track. It's not even a Working Draft (the very first level of a spec when vendors agree on the idea, but haven't iterated on the API: https://www.w3.org/policies/process/#rec-track)

> the share_target manifest reference is still way more “official” than that.

Google presents these napkin scribbles in the w3c format precisely so that gullible people would wave them around as actual specs.