6.2 Setting Tags

Tags can simply be typed into the buffer at the end of a headline. After a colon, M-TAB offers completion on tags. There is also a special command for inserting tags:

C-c C-q (org-set-tags-command)

Enter new tags for the current headline. Org mode either offers completion or a special single-key interface for setting tags, see below. After pressing RET, the tags are inserted and aligned to org-tags-column. When called with a C-u prefix, all tags in the current buffer are aligned to that column, just to make things look nice. Tags are automatically realigned after promotion, demotion, and TODO state changes (see TODO Basics).

C-c C-c (org-set-tags-command)

When point is in a headline, this does the same as C-c C-q.

Org supports tag insertion based on a list of tags. By default this list is constructed dynamically, containing all tags currently used in the buffer⁵³. You may also globally specify a hard list of tags with the variable org-tag-alist. Finally you can set the default tags for a given file using the ‘TAGS’ keyword, like

#+TAGS: @work @home @tennisclub
#+TAGS: laptop car pc sailboat

If you have globally defined your preferred set of tags using the variable org-tag-alist, but would like to use a dynamic tag list in a specific file, add an empty ‘TAGS’ keyword to that file:

#+TAGS:

If you have a preferred set of tags that you would like to use in every file, in addition to those defined on a per-file basis by ‘TAGS’ keyword, then you may specify a list of tags with the variable org-tag-persistent-alist. You may turn this off on a per-file basis by adding a ‘STARTUP’ keyword to that file:

#+STARTUP: noptag

By default Org mode uses the standard minibuffer completion facilities for entering tags. However, it also implements another, quicker, tag selection method called fast tag selection. This allows you to select and deselect tags with just a single key press. For this to work well you should assign unique letters to most of your commonly used tags. You can do this globally by configuring the variable org-tag-alist in your Emacs init file. For example, you may find the need to tag many items in different files with ‘@home’. In this case you can set something like:

(setq org-tag-alist '(("@work" . ?w) ("@home" . ?h) ("laptop" . ?l)))

If the tag is only relevant to the file you are working on, then you can instead set the ‘TAGS’ keyword as:

#+TAGS: @work(w)  @home(h)  @tennisclub(t)  laptop(l)  pc(p)

The tags interface shows the available tags in a splash window. If you want to start a new line after a specific tag, insert ‘\n’ into the tag list

#+TAGS: @work(w) @home(h) @tennisclub(t) \n laptop(l) pc(p)

or write them in two lines:

#+TAGS: @work(w)  @home(h)  @tennisclub(t)
#+TAGS: laptop(l)  pc(p)

You can also group together tags that are mutually exclusive by using braces, as in:

#+TAGS: { @work(w)  @home(h)  @tennisclub(t) }  laptop(l)  pc(p)

you indicate that at most one of ‘@work’, ‘@home’, and ‘@tennisclub’ should be selected. Multiple such groups are allowed.

Do not forget to press C-c C-c with point in one of these lines to activate any changes.

To set these mutually exclusive groups in the variable org-tags-alist, you must use the dummy tags :startgroup and :endgroup instead of the braces. Similarly, you can use :newline to indicate a line break. The previous example would be set globally by the following configuration:

(setq org-tag-alist '((:startgroup . nil)
                      ("@work" . ?w) ("@home" . ?h)
                      ("@tennisclub" . ?t)
                      (:endgroup . nil)
                      ("laptop" . ?l) ("pc" . ?p)))

If at least one tag has a selection key then pressing C-c C-c automatically presents you with a special interface, listing inherited tags, the tags of the current headline, and a list of all valid tags with corresponding keys⁵⁴.

Pressing keys assigned to tags adds or removes them from the list of tags in the current line. Selecting a tag in a group of mutually exclusive tags turns off any other tag from that group.

In this interface, you can also use the following special keys:

TAB

Enter a tag in the minibuffer, even if the tag is not in the predefined list. You can complete on all tags present in the buffer. You can also add several tags: just separate them with a comma.

SPC

Clear all tags for this line.

RET

Accept the modified set.

C-g

Abort without installing changes.

q

If q is not assigned to a tag, it aborts like C-g.

!

Turn off groups of mutually exclusive tags. Use this to (as an exception) assign several tags from such a group.

C-c

Toggle auto-exit after the next change (see below). If you are using expert mode, the first C-c displays the selection window.

This method lets you assign tags to a headline with very few keys. With the above setup, you could clear the current tags and set ‘@home’, ‘laptop’ and ‘pc’ tags with just the following keys: C-c C-c SPC h l p RET. Switching from ‘@home’ to ‘@work’ would be done with C-c C-c w RET or alternatively with C-c C-c C-c w. Adding the non-predefined tag ‘sarah’ could be done with C-c C-c TAB s a r a h RET.

If you find that most of the time you need only a single key press to modify your list of tags, set the variable org-fast-tag-selection-single-key. Then you no longer have to press RET to exit fast tag selection—it exits after the first change. If you then occasionally need more keys, press C-c to turn off auto-exit for the current tag selection process (in effect: start selection with C-c C-c C-c instead of C-c C-c). If you set the variable to the value expert, the special window is not even shown for single-key tag selection, it comes up only when you press an extra C-c.