
I use a whistle for recall and I use three toots - and I think that is the norm - I don't use for any other commands though.
I introduced by whistle feeding basically - three toots before putting dinner down.
I also used to whistle every time they came to me - be this after a verbal recall or not.
I still also use the 'here' command when they are closer.
Sorry regarding the other commands - hope this was of some help.