I have some big acronyms names and descriptions, and with this answer I could structure then well. However, now I want to put a big title in this structure, with same style as List of Tables, the text could be "List of abbreviations and acronyms".
I already searched it here, however I just saw explanations about sections and chapters. However, this list I created is something that stays out (and before) of Contents list.
Here is an example with only acronyms and each description:
\documentclass{article}
\usepackage{calc}
\usepackage{lipsum}
\makeatletter
\newcommand{\tocfill}{\cleaders\hbox{$\m@th \mkern\@dotsep mu . \mkern\@dotsep mu$}\hfill}
\makeatother
\newcommand{\abbrlabel}[1]{\makebox[5cm][l]{\textbf{#1}\ \tocfill}}
\newenvironment{abbreviations}{\begin{list}{}{\renewcommand{\makelabel}{\abbrlabel}%
\setlength{\labelwidth}{5cm}\setlength{\leftmargin}{\labelwidth+\labelsep}%
\setlength{\itemsep}{0pt}}}{\end{list}}
\begin{document}
\begin{abbreviations}
\item[US] United States
\item[EU] European Union
\item[Gvmt] Government. \lipsum[2]
\end{abbreviations}
\end{document}
