If you use Org mode extensively, you may end up with enough TODO items that it starts to make sense to prioritize them. Prioritizing can be done by placing a priority cookie into the headline of a TODO item, like this
*** TODO [#A] Write letter to Sam Fortune
By default, Org mode supports three priorities: ‘A’, ‘B’, and ‘C’.
‘A’ is the highest priority. An entry without a cookie is treated as
equivalent if it had priority ‘B’. Priorities make a difference only
for sorting in the agenda (see Weekly/daily agenda); outside the
agenda, they have no inherent meaning to Org mode. The cookies are
displayed with the face defined by the variable
which can be customized.
Priorities can be attached to any outline node; they do not need to be TODO items.
Set the priority of the current headline. The command prompts for a priority character ‘A’, ‘B’ or ‘C’. When you press SPC instead, the priority cookie, if one is set, is removed from the headline. The priorities can also be changed “remotely” from the agenda buffer with the , command (see Agenda Commands).
Increase/decrease the priority of the current headline46. Note that these keys are also used to modify timestamps (see Creating Timestamps). See also Conflicts, for a discussion of the interaction with shift-selection.
You can change the range of allowed priorities by setting the
org-default-priority. For an individual buffer, you may set these
values (highest, lowest, default) like this (please make sure that the
highest priority is earlier in the alphabet than the lowest priority):
#+PRIORITIES: A C B
See also the option