E13 (below) is a 0-3 on the canine nerd level scale: it’s relevant whether you’re a pet professional or have no animals.

E11 (below) is a 1/3 on the canine nerd level scale.

E9 (below) is a 2/3 on the canine nerd level scale.

E7 (below) is of interest for levels 1, 2 and 3 on the canine nerd level scale.

E5 (below) is a 1.5/3 on the canine nerd level scale.

E3 (below) is a 2/3 on the canine nerd level scale.