In a document class with chapters, nomencl
will set the nomenclature as an unnumbered chapter, otherwise as a section. To make the nomenclature a section even in a chaptered document like book
, add the following to your preamble:
\usepackage{etoolbox}
\makeatletter
\patchcmd{\thenomenclature}%
{\chapter*{\nomname}}%
{\section*{\nomname}}%
{}{\message{^^Jthenomenclature patching failed (1)^^J}}
\patchcmd{\thenomenclature}%
{\if@intoc\addcontentsline{toc}{chapter}{\nomname}\fi}%
{\if@intoc\addcontentsline{toc}{section}{\nomname}\fi}%
{}{\message{^^Jthenomenclature patching failed (2)^^J}}
\makeatother
Note however, that then the nomenclature, as a section, will belong to the chapter that started before, and this will show, e.g., in the Table of Contents. This might not really be what you want.
\documentclass{...}
and ending with\end{document}
.