Notification-Delay Header

The WebDAV Notification-Delay header is used in the SUBSCRIBE Method and specifies the delay the client would like the server to use in processing events. This only applies to callback notifications.

Notification-Delay:= "Notification-Delay:" 1*DIGIT

If the SUBSCRIBE Method request does not also include a Call-Back Header, the Notification-Delay header is ignored.

If the client explicitly requested a notification delay, the server must include in its response an identical header containing the notification delay that it will use. The server may return a value that is greater or less than the value requested by the client, allowing the server to dictate a minimum delay, a maximum delay, or to return a less granular delay. For example, the server may round up a request from 0.24 to 0.25.

The header is also valid in a subscription refresh and indicates a request to change the notification delay. If the server does not support changing the notification delay but otherwise will refresh the subscription, it must respond with a 200 (OK) response, and include the Notification-Delay header with the original value.