In large documents it is often useful to have a page reserved for the list of acronyms. I've tried several approaches to this and after a discussion at pandoc-discuss the following solution was suggested. The author suggested the use of the package acronyms, but I found it easier to work with the package acro.
It will look like:

This solution comes in the form of a mighty_make theme. The steps to get this going is to download mighty_make's testing branch:
wget http://tiny.cc/mighty_test -O MakefileThen adding the theme and the dependencies (panflute) with:
make fetch THEME="https://github.com/lf-araujo/pandoc-acronyms"
sudo apt install python-pip
pip install panfluteIn the yaml metadata the following should be added:
---
acronyms: yes
---In the body of your document the syntax to follow is: [WHO](acro "World Health Organization") will include a line in the Acronyms page with World Health Organization. Whenever you want to refer to WHO again in the body, you should use [WHO](acro). You can use this syntax as many times as needed, you can even reorganize the contents of your text (like move one chapter up the document) and the tool will detect this change and expand WHO only in the first time it appears in the document.
Finally, include the following where you want to add the list of acronyms in your document:
\newpage
\printacronyms