PRBool isCritical

Should the client or server abort if the control is not understood? Should be set to false for server controls used in abandon and unbind operations, since those have no server response.

ACString oid

Control type, represented as a string.

nsILDAPBERValue value

The data associated with a control, if any. To specify that no data is to be associated with the control, don't set this at all (which is equivalent to setting it to null).