Sometimes you want to keep information associated with an entry, but you
normally don't want to see it. For this, Org mode has drawers.
Drawers need to be configured with the variable
org-drawers1. Drawers
look like this:
** This is a headline
Still outside the drawer
:DRAWERNAME:
This is inside the drawer.
:END:
After the drawer.
Visibility cycling (see Visibility cycling) on the headline will hide and show the entry, but keep the drawer collapsed to a single line. In order to look inside the drawer, you need to move the cursor to the drawer line and press <TAB> there. Org mode uses a drawer for storing properties (see Properties and Columns), and another one for storing clock times (see Clocking work time).
[1] You can define drawers on a per-file basis
with a line like #+DRAWERS: HIDDEN PROPERTIES STATE