Question

When using Org-mode to create beamer presentation it is possible to set the property of a heading such that the exported heading is not shown but only its contents. For instance, the following

#+title: Test

#+options: toc:nil
#+latex_class: beamer
#+startup: beamer

#+BEAMER_FRAME_LEVEL: 2

* Ignored heading                                           :B_ignoreheading:
:PROPERTIES:
:BEAMER_env: ignoreheading
:END:
Text

Result in a frame with “Text” only and no heading. Is this kind of functionality available for non-beamer documents? That is, is it possible to tell Org-mode to not export a heading but only its contents? For instance, would it be possible to make Org-mode export the following

#+title: Test

* Ignored heading
Text

without exporting the heading “Ignored heading” but only “Text”?

If I export

#+title: Test

* 
Text

(note the space after *) to LaTeX I get the following (I only included the relevant part):

\section{}

Text

But this is not what I want. I want the heading to be completely ignored in the export so that I would get the following (again I only include the relevant part):

Text

Answer 1

There is no default support for what you are asking. However you can use
a preprocess hook to get a similar output. Here is an example for LaTeX export:

;; backend aware export preprocess hook
(defun sa-org-export-preprocess-hook ()
  "My backend aware export preprocess hook."
  (save-excursion
    (when (eq org-export-current-backend 'latex)
      ;; ignoreheading tag for bibliographies and appendices
      (let* ((tag "ignoreheading"))
        (org-map-entries (lambda ()
                           (delete-region (point-at-bol) (point-at-eol)))
                         (concat ":" tag ":"))))))

(add-hook 'org-export-preprocess-hook 'sa-org-export-preprocess-hook)

This is a snippet from my org-mode setup. You can see the original on
github.
The above code will ignore headings tagged with ignoreheading, e.g.

* Heading 1
* Heading 2                           :ignoreheading:
+ Some text
+ an item

gets exported as:

\section{Heading 1}
\label{sec-1}

\begin{itemize}
\item Some text
\item an item
\end{itemize}

Caveat: There is a known issue with this solution. It
does not work when you try this on the very first headline. I don’t
understand why that is the case, hopefully I’ll have time someday to
investigate.

Workaround to caveat: The above limitation can be
circumvented for LaTeX export by using a line like this after the org
file header:

\include{preamble.tex}

The preamble.tex file can include sections like an abstract or
acknowledgements. However you should note this makes your org file very
closely tied to the export backend. It would become non-trivial to
export the same org file to HTML for example.

Note: For a similar setup with the new export framework (Org
8.0 or higher), use the following:

(defun sa-ignore-headline (contents backend info)
  "Ignore headlines with tag `ignoreheading'."
  (when (and (org-export-derived-backend-p backend 'latex 'html 'ascii)
          (string-match "\\`.*ignoreheading.*\n"
                (downcase contents)))
    (replace-match "" nil nil contents)))

(add-to-list 'org-export-filter-headline-functions 'sa-ignore-headline)