clipboard property

Whether to allow sites to access the clipboard via advanced capabilities of the Async Clipboard API. "Advanced" capabilities include anything besides writing built-in formats after a user gesture, i.e. the ability to read, the ability to write custom formats, and the ability to write without a user gesture. One of allow: Allow sites to use advanced clipboard capabilities, block: Don't allow sites to use advanced clipboard capabilties, ask: Ask when a site wants to use advanced clipboard capabilities. Default is ask. The primary URL is the URL of the document which requested clipboard access. The secondary URL is not used.