Section markers are placed with the section tool.
You will have options in the section settings as to how you want the marker to look.
Labels are added with the label tool.
I assume they would be just an 'autotext label' that allows you to type what ever you want to see.
Door and window tags (markers) can be set in the door/window settings.
You will have different markers to what I show here.
The visibility of the marker is controlled in the Model View Options.
Note, this image is version 22 but very similar in 25 & 26.
One of the forum moderators.
Versions 6.5 to 25
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Dell Precision 3510 - i7 6820HQ @ 2.70GHz, 16GB RAM, AMD FirePro W5130M, Windows 10