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-c

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

Org will support tag insertion based on a list of tags. By default this list is constructed dynamically, containing all tags currently used in the buffer. 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 with lines 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 option line to that file:

     #+TAGS:

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 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 option line as:

     #+TAGS: @work(w)  @home(h)  @tennisclub(t)  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.

Don't forget to press C-c C-c with the cursor in one of these lines to activate any changes.

To set these mutually exclusive groups in the variable org-mode-alist you must use the dummy tags :startgroup and :endgroup instead of the braces. 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 will automatically present you with a special interface, listing inherited tags, the tags of the current headline, and a list of all valid tags with corresponding keys¹. In this interface, you can use the following keys:

a-z...

Pressing keys assigned to tags will add or remove them from the list of tags in the current line. Selecting a tag in a group of mutually exclusive tags will turn off any other tags from that group.

<TAB>

Enter a tag in the minibuffer, even if the tag is not in the predefined list. You will be able to complete on all tags present in the buffer.

<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 will display 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> <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 will immediately exit 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.