
I'm sorry, but they are wrong. If it's 'A small bevel', then why do they need to call it an arris, they seem to be hedging their bets

………. a canted plane (ground or otherwise), at angles of usually less, or more than, 90 degrees, has always been known as a bevel, or sometimes a chamfer (mostly in woodwork, I think).
I suspect they are confusing a very small bevel with an arris, which is why they comment 'of width not exceeding 1/16 of an inch' - they are allowing for intersections of planes to be interrupted by a narrow plane, which might be bevelled to the tune of 1/16 of an inch.
So by definition it isn't an arris, but a bevel albeit rather narrow - and is simply another plane surface, not an arris - for which the definition is the intersection of two plane surfaces, without anything in between.
Most cut tops will have a small bevel on their insides - it prevents potential chipping or cut fingers, which would likely happen with an arris.
of course, you can describe something however you like provided people understand what it is you're speaking about.