2.2.1.4.8.5 seekable

Indicates that the server supports seeking within the content using the stream-time (section 2.2.1.4.28) token and the stream-offset (section 2.2.1.4.25) token.

If the playlist feature token is specified, and the client version is less than 9.0 (as specified by the client in the User-Agent header), the seekable feature token MUST NOT be specified.