This deprecation removes the ability to use "," as a separator between items in a permissions policy declaration (feature policy declaration) in an iframe tag. Developers should switch to ";" as the correct separator.


Chrome currently recognizes a non-standard "," as a separator between items in an iframe "allow" attribute. This behaviour is an accidental side effect of the way that we parse the attribute using the same parser as the 'Feature-Policy' header. (Commas were allowed by the header parser to support concatenating multiple headers together, but the attribute was always specced to contain a single serialized policy.)


Specification link

Unknown standards status - check spec link for status

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.

  • In development
  • Shipped/Shipping
  • No signals


Last updated on 2021-12-31