Standard header fields and messages MUST NOT begin with the leading characters “P-“. Reserved to avoid conflict with . Cause for protocol failure of GTP-C supporting WLAN, as a representation in decimal digits of the received binary value. Cause for protocol failure of IKEV2 supporting untrusted Binary option indicator v22, as a representation in decimal digits of the received binary value.
This option tag is for support of the Answer-Mode and Priv-Answer-Mode extensions used to negotiate automatic or manual answering of a request. A UA adding the early-session option tag to a message indicates that it understands the early-session content disposition. This option tag identifies an extension to REFER to suppress the implicit subscription and provide a URI for an explicit subscription. This option tag is used to indicate that a UA supports changes to URIs in From and To header fields during a dialog. The “geolocation-http” option tag signals support for acquiring location information via an HTTP . A location recipient who supports this option can request location with an HTTP GET and parse a resulting 200 response containing a PIDF-LO object.