Make glossary for your LaTeX work.

% At first add these two lines in your preamble to load the glossary package and create refence.
\usepackage{glossary}
\makeglossary

% This line is for your output.
\printglossary

% In document you can create your glossary entry like this:
GPL\glossary{name={GPL}, description={General Public License}}

At last, you must run this command in your terminal:

makeindex -s yourfile.ist -t yourfile.glg -o yourfile.gls yourfile.glo