Good point Sue! So, I waded through the various clauses and statements of the CFIA labelling regulations, in regards to Nutrient Content Claims.

We see from section 6.2.2.2 just what constitutes the designation of "significant source" (which is a US term, in Canada it's called "good source" or "high in" ) .. The food doesn't necessarily contain 20 GRAMS of protein per serving, what they do is multiply the efficiency or bioavailability of the protein times the number of grams per "reasonable daily serving" of the food. There's a chart showing some examples of the Protein Ratings of various foods in section 6.4.2

Foods with a Protein Rating (PR) of 20 or more are permitted to be labelled as a "good source of" or "significant source of" ..

2 eggs are considered a "reasonable serving size' and have 12.8g protein .. and a PR of 48.6.

100g (3.5 oz) beef has 21g protein, and a PR of 67.2.

5 slices of white bread have 12.6g prot, and a PR of 12.6

If the PR of pork rinds falls below 20, the reason is most likely due to the tiny portion size as we originally thought, but not for the obvious reason

Doreen