Original: Others are breeding Labradoodle to Labradoodle over successive generations, and trying to establish a new dog breed.
Simplified: There are many variations of Labradoodles with the F1b being the most common and was created by St. Clair Labradoodle Kennelsby crossing an F1 Labradoodle back to a poodle. This is known as a "backcross" Labradoodle and improves the coat qualities of the breed.