Plumbing Course

Good afternoon everyone,
I am doing the plumbing course and after reading this:

*"4.9 Clearance for Water Closets & Lavatories

There should be at least 15 inches of space from the center of a water closet, lavatory or bidet to any sidewall, partition, cabinet or any other obstruction. There should be at least 30 inches of space between adjacent fixtures. There should be a space of at least 21 inches in front of the water closet, lavatory or bidet to any wall, fixture or door. This clearance is for comfortable, adequate space for cleaning and use of the fixture."*
*
· fixture: In plumbing, the devices that provide a supply of water and/or its disposal, such as sinks, tubs and toilets.*

I am wondering if this is one of those ideal cases that are no were to be found?

I normally see the edge of the tubs as close as 6 inches from the edge of the toilet.

These are standard building code requirements. If there is an obvious obstruction, call it out, but I doubt anyone will move the toilet.

Thats was my point, who will move a working toilet if the only deficiency is clearance.