The BGS grading up ladder to British Guernsey:- 1) IR (Identification
Register) - any female of any age. For BG purposes no
Nubian/Munchie/Mini blood.

2) SR (Supplementary Register) - female any age with a GG sire.

3) FB (Foundation Book) - female maximum two yrs with GG sire and SR dam.

4) HB1 (Herd Book ) - female maximum two yrs with GG sire and FB dam.

5) HB2 (Herd Book) - female or male maximum 2 yrs with GG sire and HB1 dam.

6) BG (British Guernsey) - female or male maximum 2 yrs with GG sire
and HB2 dam.

That is the shortest route using maximum GG blood therefore best chance
of correctly marked kids. You CAN use HB2 bucks but will add at least
one extra generation.

Goats are eligible for a Breed Section (including BG) if:-
a) Both sire and dam are BG.
b) One parent is BG and the other is GG.
c) The dam is BG and has been AI'd with GG semen.
d) One parent is GG/BG and three grandparents + the sire of the fourth
grandparent are entered in the BG and/or the GG Section.