Guersney registration

Hey has any one came across doing a vechile from guersney ? don't contain letters; they only feature numbers. Plates show up to six characters which are often displayed in silver on a Black background I’ve got one booked in soon it’s on a 2016 vechile does the number plate plate rules not apply as you do not have to check foreign registered vehicles? I no our place the mot tester passed it last year
Tia