org: Fast access to TODO states

 
 5.2.4 Fast access to TODO states
 --------------------------------
 
 If you would like to quickly change an entry to an arbitrary TODO state
 instead of cycling through the states, you can set up keys for
 single-letter access to the states.  This is done by adding the
 selection character after each keyword, in parentheses(1).  For example:
 
      (setq org-todo-keywords
            '((sequence "TODO(t)" "|" "DONE(d)")
              (sequence "REPORT(r)" "BUG(b)" "KNOWNCAUSE(k)" "|" "FIXED(f)")
              (sequence "|" "CANCELED(c)")))
 
    If you then press ‘C-c C-t’ followed by the selection key, the entry
 will be switched to this state.  ‘SPC’ can be used to remove any TODO
 keyword from an entry.(2)
 
    ---------- Footnotes ----------
 
    (1) All characters are allowed except ‘@^!’, which have a special
 meaning here.
 
    (2) Check also the option ‘org-fast-tag-selection-include-todo’, it
 allows you to change the TODO state through the tags interface (See
 Setting tags), in case you like to mingle the two concepts.  Note that
 this means you need to come up with unique keys across both sets of
 keywords.