The implementation is trivial but entirely useless and has been since 2012. The attribute is not present at all in Gecko. It has been removed from the spec:


Specification link

Specification being incubated in a Community Group

Status in Chromium


Deprecated (tracking bug)

Consensus & Standardization

After a feature ships in Chrome, the values listed here are not guaranteed to be up to date.

  • No signal
  • No signal
  • No signals


Last updated on 2021-08-29