As soon as we use the dyndns wizard, it is not possible any more to erase the corresponding field and it even by using the custom, the only solution: mark disable in the menu.
I glimpse another solution: be able to leave space the custom zone to reset without having to get(touch) the file ini.
procedure forceDynDNSupdate(url:string='');
const
MSG = 'This option makes pointless the option "Find external address at startup", which has now been disabled for your convenience.';
begin
dyndns.url:=url;
if url='' then exit;
// this function is called when setting any dyndns service.
....
It was, either adopt this solution which has no consequence on the rest of the program, or to add a menu clear above disable
