How can I accomplish similar side notes?

Question

I would like to add side notes to my document as in the example below, but I do not know how. I will be grateful for any suggestions.

Answer 1

A default \todo from the todonotes package does something similar to what you're asking, so if you're not using todonotes already, the following might be useful.

\todo does draw a coloured box around the margin note, but changing the bordercolor and backgroundcolor as below removes that.

\documentclass{article}
\usepackage[
 bordercolor=none,
 backgroundcolor=none,
 linecolor=gray
]{todonotes}
\begin{document}
Bla bla etc., uzw., osb., Lorem ipsum dolor \todo{Foo bar}{} and so on and so forth.
\end{document}

It's possible to redefine some macros to get output more like your image.

\documentclass{article}
\usepackage[
 bordercolor=none,
 backgroundcolor=none,
 linecolor=gray
]{todonotes}
\usetikzlibrary{arrows.meta}
\tikzset{
  smallcirc/.tip={Circle[width=2pt,length=2pt]},
  % connectstyle is used for the line drawing to the marginnote,
  % add the arrow tip on each end, and make it thin
  connectstyle/.append style={smallcirc-smallcirc,thin}
}
\makeatletter
\renewcommand{\@todonotes@drawLineToRightMargin}{%
\begin{tikzpicture}[remember picture, overlay]%
\draw[connectstyle]%
(inText) -- ([yshift=-0.2cm] inText)% %% <--- added "(intext) --"
-| (inNote.west);% %% <--- removed "-| ([xshift=-0.2cm] inNote.west)"
\end{tikzpicture}%
}%
\renewcommand{\@todonotes@drawLineToLeftMargin}{%
\begin{tikzpicture}[remember picture, overlay]%
\draw[connectstyle]%
(inText) -- ([yshift=-0.2cm] inText)% %% <--- added "(intext) --"
-| (inNote.west);% %% <--- removed "-| ([xshift=-0.2cm] inNote.west)"
\end{tikzpicture}%
}%
\makeatother

\begin{document}
Bla bla etc., uzw., osb., Lorem ipsum dolor \todo{Foo bar}{} and so on and so forth.
\end{document}