Is it possible to have two or more tags that are "peers," i.e., all equal,
not in a hierarchy, be in an ad-hoc, as-needed way be hierarchical? For
example, I have the tags *org-mode, lisp, *and *emacs, *and I want to have
a header with the tags

* my header    :emacs:org-mode:lisp:

So the above should be an ad-hoc hierarchy of

- emacs
   - org-mode
      - lisp

As I understand, the order indicates the level in a hierarchy. True? So the
above has *emacs* at the top of the tag hierarchy, then *org-mode, *then *lisp.
*Correct? So yes, I could simply set up this hierarchy. But what I really
want is to not have these tags in any set hierarchy, rather, be able to use
them independently, mix-and-match, e.g.,

* Another Header    :emacs:lisp:

or maybe

* Yet Another Header   :lisp:

and this would be just about non-Emacs, non-org-mode Lisp. Is this
mix-and-match possible?

LB