Dear emacs-orgmode moderators:

I would like to use \ul from the soul package in Org mode for underlining with line breaks (and *not* underlining spaces). It’s not working well. It fails like \underline (spaces get underlined, and lines don’t break and run off the page). My LaTeX export doesn’t work if I insert \ul{abc} into the org file, but I can insert \ulem{abc} or \underline{abc}, as well as the typical _abc_.

More information: I’m actually trying to define a new command using logic in the LaTeX header. This way, I can make notes with key words. I can toggle a Boolean variable, and it makes key words show up; or, it underlines the words, which are also hidden by \phantom. Also, we would like to avoid underlining spaces because it cues the reader to know how many words are missing.

I note this previous discussion:
   https://lists.gnu.org/archive/html/emacs-orgmode/2013-06/msg00376.html

It seems like the issue that was fixed at one point and \ul should work, but maybe it’s not now. Or, maybe I don’t have the experience to know how to apply the solution to my Emacs/Org mode on my computer.

FYI, I’m using org-9.3.6 from ELPA with Aquamacs 3.5, which includes GNU Emacs 25.3.50.1. I’m working on macOS X 15.7 (Catalina).

Thanks for any help or instructions you can provide. I’m not very experienced at elisp, so I don’t know how to fix this locally, but I’m happy to try if you tell me. It looks like I may be able to do something with org-latex-text-markup-alist locally, but I don’t know what or how.

I will include my org text below, noting that \underline works in the :+latex_header: lines, but \ul doesn’t.

Kind regards,
Enrique B.

==== Org doc starts below here ====
#+EXPORT_SELECT_TAGS: export
#+EXPORT_EXCLUDE_TAGS: noexport

#+latex_class_options: [12pt]
#+latex_header: \usepackage[margin=1in]{geometry}
#+latex_header: \newif\ifsolution % define a solution Boolean variable
#+latex_header: \solutiontrue % specify the value of the Boolean switch

#+latex_header: \ifsolution
#+latex_header:    \newcommand{\keyText}[1]{\underline{{\color{blue} \Large #1}}}
#+latex_header: \else
#+latex_header:    \newcommand{\keyText}[1]{\underline{{\phantom{ \Large #1}}}}
#+latex_header: \fi

#+options: toc:nil

* This will be exported                                              :ignore:
The solution text is here.

My message to you is: \keyText{Hello world}.
- Now, let us try some really long key text--so long that it even spans
  multiple \keyText{lines. That line is this line, for so I have written it.}