Tweak the sections on easy LaTeX preamble editing

README.org

@@ -3794,11 +3794,19 @@ define the [[https://orgmode.org/][Org mode]] =kbd= macro in listing
 :CUSTOM_ID: sec:testing-org
 :END:
 
-Listing [[lst:setup-org-mode-test-1]] and [[lst:setup-org-mode-test-2]] provide
-facilities for [[https://orgmode.org/worg/org-tests/index.html][Testing Org]].
+Listing [[lst:batch-org-testing]] shows the recommended way: use =make test= in a
+clean Org git repository.  Listing [[lst:setup-org-mode-test-1]] and
+[[lst:setup-org-mode-test-2]] provide facilities for [[https://orgmode.org/worg/org-tests/index.html][Testing Org]] interactively.
+
+#+caption[Batch Org testing]:
+#+caption: Batch Org testing: obligatory before mailing a patch.
+#+name: lst:batch-org-testing
+#+begin_src shell -n :eval never :tangle no
+make test > out.txt 2>&1
+#+end_src
 
 #+caption[Testing Org facilities 1]:
-#+caption: Testing Org facilities 1.
+#+caption: Testing Org facilities 1: for use during development only.
 #+name: lst:setup-org-mode-test-1
 #+begin_src emacs-lisp -n
 (with-eval-after-load 'emacs
@@ -3841,7 +3849,7 @@ facilities for [[https://orgmode.org/worg/org-tests/index.html][Testing Org]].
 #+end_src
 
 #+caption[Testing Org facilities 2]:
-#+caption: Testing Org facilities 2.
+#+caption: Testing Org facilities 2: for use during development only.
 #+name: lst:setup-org-mode-test-2
 #+begin_src emacs-lisp -n
 (with-eval-after-load 'emacs
@@ -3888,7 +3896,7 @@ Examples: `ob/' or `ob-maxima'."
         (ert text)))))
 #+end_src
 
-*** [[info:org#Noweb Reference Syntax][Noweb (info)]] trickery
+*** LaTex preamble editing using [[info:org#Noweb Reference Syntax][Noweb (info)]]
 :PROPERTIES:
 :CUSTOM_ID: sec:file-inclusion-and-noweb
 :END:
@@ -4105,15 +4113,17 @@ handled by [[info:org#Noweb Reference Syntax][noweb (info)]].
 <<latex-header-5>>
 #+end_src
 
-*** [[info:org#LaTeX header and sectioning][Deprecated easy LaTeX preamble editing methods]]
+*** [[info:org#LaTeX header and sectioning][Deprecated LaTeX preamble editing methods]]
 :PROPERTIES:
 :CUSTOM_ID: sec:easy-latex-preamble-editing
 :END:
 
-There are at least two deprecated (old and historic) ways to edit the LaTeX
-preamble =latex_header= and =latex_extra_header= export options easily in LaTeX
-source or export blocks.  This [[info:org#Top][Org (info)]] file uses the recommended method of
-noweb trickery in Section [[#sec:file-inclusion-and-noweb]].
+*NOTE:* This [[info:org#Top][Org (info)]] file uses the recommended method of noweb trickery in
+Section [[#sec:file-inclusion-and-noweb]].
+
+There are at least two deprecated (old and historic) ways to edit the Org
+=#+latex_header:= and =#+latex_extra_header:= keywords easily
+for export to LaTeX, see [[info:org#LaTeX header and sectioning][LaTeX header and sectioning (info)]].
 
 The old way -- exploiting an idea of [[https://www.matem.unam.mx/~omar/][Omar Antolin Camarena]] -- is to code new
 [[info:org#Editing Source Code][<LANGUAGE>-modes]] allowing to edit in LaTeX mode and to export to LaTeX code with
@@ -4125,6 +4135,17 @@ exposing his idea:
 Listing [[lst:org-babel-latex-header-blocks]] implements this way by means of two
 new [[info:org#Editing Source Code][<LANGUAGE>-modes]]: =latex-header= and =latex-extra-header=.
 
+The old way is to define two Org Babel languages (=latex-extra-header= and
+=latex-header=) as done in Listing [[lst:org-babel-latex-header-blocks]]. The
+historic way is to use a special export attribute as in the function
+=org-latex-header-blocks-filter= in [[https://git.sr.ht/~bzg/org-contrib/tree/master/item/lisp/ox-extra.el][ox-extra.el]].  Apparently, nobody is using
+this broken function (broken, since it relies on support only in org-mode before
+=2014-11-11=).  Listing [[lst:org-latex-header-blocks-filter]] proposes a fix for
+=org-latex-header-blocks-filter=.  This setup keeps the deprecated ways for
+backwards compatibility.  A practical difference is that new way source blocks
+(contrary to old way export blocks) do not work in [[info:org#Export Settings][#+SETUPFILE: <FILE>]], but only
+in [[info:org#Export Settings][#+INCLUDE: <FILE>]] files.
+
 #+caption[New =<LANGUAGE>-modes= to edit the LaTeX preamble easily]:
 #+caption: Add =latex-header= and =latex-extra-header=  language modes to edit
 #+caption: LaTeX preamble =latex_header= and =latex_extra_header= export options
@@ -4163,12 +4184,6 @@ prefixes all lines with \"#+latex_header: \"."
     (add-to-list 'org-src-lang-modes '("latex-extra-header" . latex))))
 #+end_src
 
-The historic way is to use a special export attribute as in the function
-=org-latex-header-blocks-filter= in [[https://git.sr.ht/~bzg/org-contrib/tree/master/item/lisp/ox-extra.el][ox-extra.el]].  Apparently, nobody is using
-this broken function (broken, since it relies on support only in org-mode before
-=2014-11-11=).  Listing [[lst:org-latex-header-blocks-filter]] proposes a fix for
-=org-latex-header-blocks-filter=.
-
 #+caption[Convert marked LaTeX export blocks to LaTeX header lines]:
 #+caption: Convert marked LaTeX export blocks to LaTeX header lines.
 #+name: lst:org-latex-header-blocks-filter
@@ -4219,11 +4234,6 @@ converts to
               org-export-before-parsing-functions))
 #+end_src
 
-This file uses the new most simple way, while keeping the deprecated ways for
-backwards compatibility.  A practical difference is that new way source blocks
-(contrary to old way export blocks) do not work in [[info:org#Export Settings][#+SETUPFILE: <FILE>]], but only
-in [[info:org#Export Settings][#+INCLUDE: <FILE>]] files.
-
 *** [[info:org#HTML Export][HTML export (info)]]
 :PROPERTIES:
 :CUSTOM_ID: sec:html-export