To highlight keywords turn on hl-todo-mode in individual buffers or use the global variant global-hl-todo-mode.

You can customize the keywords that are recognized by customizing hl-todo-keyword-faces either through the customization interface or by setting the variable directly in your init file, for example:

(setq hl-todo-keyword-faces
      '(("TODO"   . "#FF0000")
        ("FIXME"  . "#FF0000")
        ("DEBUG"  . "#A020F0")
        ("GOTCHA" . "#FF4500")
        ("STUB"   . "#1E90FF")))

This package also provides commands for moving to the next or previous keyword, to invoke occur with a regexp that matches all known keywords, and to insert a keyword. If you want to use these commands, then you should bind them in hl-todo-mode-map, e.g.:

(keymap-set hl-todo-mode-map "C-c p" #'hl-todo-previous)
(keymap-set hl-todo-mode-map "C-c n" #'hl-todo-next)
(keymap-set hl-todo-mode-map "C-c o" #'hl-todo-occur)
(keymap-set hl-todo-mode-map "C-c i" #'hl-todo-insert)

See FAQ and Common Issues if something isn’t working as expected.

• Command hl-todo-occur uses occur to list TODO keywords.
• Command hl-todo-rgrep uses rgrep to list TODO keywords.
• Function hl-todo-flymake teaches flymake about TODO keywords.
• Package flycheck-hl-todo adds TODO keywords to flycheck.
• Package magit-todos displays TODO keyboards in magit’s status buffer.
• Package consult-todo supports searching and jumping to TODO keywords using consult.