A clipboard-client% object is associated to an eventspace when it becomes the current client; see set-clipboard-client for more information.

The format string is typically four capital letters. (On Mac OS, only four characters for format are ever used.) For example, "TEXT" is the name of the UTF-8-encoded string format. New format names can be used to communicate application- and platform-specific data formats.

Only data format names in the client’s list will be passed to this method; see add-type.

When this method is called by the clipboard, the current eventspace is the same as the client’s eventspace. If, at the point of the clipboard request, the current eventspace is not the client’s eventspace, then current thread is guaranteed to be the handler thread of the client’s eventspace.