6 Tags ¶

An excellent way to implement labels and contexts for cross-correlating information is to assign tags to headlines. Org mode has extensive support for tags.

Every headline can contain a list of tags; they occur at the end of the headline. Tags are normal words containing letters, numbers, ‘_’, and ‘@’. Tags must be preceded and followed by a single colon, e.g., ‘:work:’. Several tags can be specified, as in ‘:work:urgent:’. Tags by default are in bold face with the same color as the headline.

Tag inheritance ¶

Tags make use of the hierarchical structure of outline trees. If a heading has a certain tag, all subheadings inherit the tag as well. For example, in the list

* Meeting with the French group      :work:
** Summary by Frank                  :boss:notes:
*** TODO Prepare slides for him      :action:

the final heading has the tags ‘work’, ‘boss’, ‘notes’, and ‘action’ even though the final heading is not explicitly marked with those tags.

You can also set tags that all entries in a file should inherit just as if these tags were defined in a hypothetical level zero that surrounds the entire file. Use a line like this⁶:

#+FILETAGS: :Peter:Boss:Secret:

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.

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 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 using the ‘TAGS’ keyword, like

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

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)

Tag groups ¶

A tag can be defined as a group tag for a set of other tags. The group tag can be seen as the “broader term” for its set of tags.

You can set group tags by using brackets and inserting a colon between the group tag and its related tags:

#+TAGS: [ GTD : Control Persp ]

or, if tags in the group should be mutually exclusive:

#+TAGS: { Context : @Home @Work }

When you search for a group tag, it return matches for all members in the group and its subgroups. In an agenda view, filtering by a group tag displays or hide headlines tagged with at least one of the members of the group or any of its subgroups.

If you want to ignore group tags temporarily, toggle group tags support with org-toggle-tags-groups, bound to C-c C-x q.

Tag searches ¶

C-c / m or C-c \ (org-match-sparse-tree)

Create a sparse tree with all headlines matching a tags search. With a C-u prefix argument, ignore headlines that are not a TODO line.

M-x org-agenda m (org-tags-view)

Create a global list of tag matches from all agenda files. See Matching Tags and Properties.

M-x org-agenda M (org-tags-view)

Create a global list of tag matches from all agenda files, but check only TODO items.

These commands all prompt for a match string which allows basic Boolean logic like ‘+boss+urgent-project1’, to find entries with tags ‘boss’ and ‘urgent’, but not ‘project1’, or ‘Kathy|Sally’ to find entries which are tagged, like ‘Kathy’ or ‘Sally’. The full syntax of the search string is rich and allows also matching against TODO keywords, entry levels and properties. For a more detailed description with many examples, see Matching Tags and Properties.