If you use a pdf-viewer to add comments to a pdf document, you do not modify the typesetting - of course.
I would like to have the same behaviour using a command of the pdfcomment package (or other package).
My problem is, that pdfcomment in some cases adds vertical space in the text.
\documentclass{article}
\usepackage{pdfcomment}
\begin{document}
\section{Section 1 Title}
\pdfmargincomment{This leads to additional vertical space :-(}
\begin{itemize}
\item additional vertical space above :-(
\end{itemize}
\section{Section 2 Title}
\begin{itemize}
\item normal vertical space above :-)
\end{itemize}
\end{document}


\marginpar{\pdfcomment{Hello}}seems to be more robust than\pdfmargincomment{Hello}if you place it between\section{test1}and\subsection{test2}e.g. – Tobias Jul 27 '16 at 22:12