The BCA specs are even more relaxed because they cover home tables. I think pockets are OK up to 5 1/8 or so.Most sports have clearly defined specs -- pool not so much. I just looked at WPA and it says 4-1/2" to 4-5/8" corner pockets under their :
"Recommended Equipment Specifications"
I added the quotation marks -- but the word "recommended" is right there in the heading.
It also says, "At its sole discretion, the World Pool-Billiard Association can sanction tournaments on tables not in compliance with these specifications."