Tag Hierarchy (Mastering Org-Mode)

1.15.2 Tag Hierarchy

Tags can be defined in hierarchies. Defining multiple group tags and nesting them creates a hierarchy. Can create a taxonomy of terms to classify nodes. When searching for a group tag, the search returns all members of the group and subgroups.

#+TAGS: [ GTD : Control Persp ]
#+TAGS: [ Control : Context Task ]
#+TAGS: [ Persp : Vision Goal AOF Project ]

GTD
- Persp
  - Vision
  - Goal
  - AOF
  - Project
- Control
  - Context
  - Task

(setq org-tag-alist '((:startgrouptag)
                  ("GTD")
                  (:grouptags)
                  ("Control")
                  ("Persp")
                  (:endgrouptag)
                  (:startgrouptag)
                  ("Control")
                  (:grouptags)
                  ("Context")
                  ("Task")
                  (:endgrouptag)))