What do these abbreviations stand for?

[elouiseot]

Can anyone tell me what the following abbreviations mean in relation to affiliated dressage competitions?
CDIO
CDI
CDIYJ
E.g. Hickstead CDIO**/CDI***/CDIYJ

 

[ForeverBroke_]

Pfft! No idea. Sorry!

Cumilitave dressage....

Nope, give up

 

[MrsMozart]

CDIO - Can Donkeys Inch Over
CDI - 'Can't Decide' Innit
CDIYJ - 'Can't Decide' Innit Ya Jamjar

Sorry...

 

[jumpthemoon]

I think CDI stands for Concours de Dressage International but not sure about the others