Do you remember proper sizes for traps and fixtures drains?

I’m going through a manual that claims that inspectors are usually expected to know the proper sizes for traps and fixture drains. Do you actually have these memorized, or do you just look for traps and drains that look improperly sized and confirm as necessary?

Ooops, should have included a choice for plumber evaluation.

Only two sizes for residential isn’t there?
I was just thinking sinks when I read this so that might include showers, toilets, floor drains, etc… So I will stick with memorized. LOL

I’m OK with the minimum sizes, but some, such as showers may have larger requirements due to the GPM rating of the fixtures. I once did a custom home with a shower that was larger than the typical bedroom. It had its own waterfall and IIRC something like 24 Kohler shower heads. It also had a single 1.5-inch dia drain. I ran the numbers on it and determined that it required a 3 or 4-inch drain based on the combined capacity of all the shower heads (I forget which). I had to go to the books for that one.