What do F1, F2B, etc. mean?

The terms F1, F2B, etc. specify the generation of the Goldendoodle, as detailed below.

First Generation (F1) Goldendoodle: Golden Retriever + Poodle
First Generation Backcross (F1B) Goldendoodle: F1 Goldendoodle + Poodle
Second Generation (F2) Goldendoodle: F1 Goldendoodle + F1 Goldendoodle
Second Generation Backcross (F2B) Goldendoodle: F1 Goldendoodle + F1B Goldendoodle OR F1B Goldendoodle + F1B Goldendoodle

All further crossings are simply referred to as multigenerational.

Additional information on generation breeding is available at http://www.goldendoodles.com/faqs/generations.htm