In the window that appears, select from one to three marks. When you choose a third mark, the remaining three becomes disabled and cannot be selected because one reservation can be assigned with up to three marks.
Each mark (color) can be named by clicking on the edit button.
1.That is special room description, which can help you to differ room fast in planning.
You can find it on the right from room number. For example: sea view, balcony e.t.c