Combination Wye On Its Back/Side

I was underneath the house the other day and noticed a couple of combination wyes in the plumbing on their backs/sides.

I know there are differences on which fittings can be on their sides/back and I was curious if these were done correctly. We moved into the house about a year and a half ago and my best guess is that these pipes were redone about 5 years ago - but based on the previous owner's other handiwork I wouldn't be surprised if the entire DWV system is wacky.

First one is the drain from a bathroom sink. The vertical continues as a vent through the roof.

On the second, if you can look past the mess of romex (another project for another day) two toilets connect into the main stack with a combination wye on its side.

A combo is the same as a Y and 45. Perfectly fine.

John

The combos are fine. A sanitary tee would be improper.

The strapping used is a bit hokey, as is the NM wire that could use some cable staples.

The fittings are installed correctly.

Thanks for the replies!

If you think the strapping and NM look hokey - you don't even want to see the rest of the basement! We gutted the upstairs and started over - it was bad.