Text Formatting ⇒ Starting an 'enumerate' item with a left bracket?

[JasonM]

An annoying problem that I cannot figure out:

In an enumerate environment:

Code: Select all

\begin{enumerate}[a.] 
\item Whatever1
\item *[Whatever2]
\item [Whatever3]
\end{enumerate}

The third item (and any item beginning with a left/open bracket) gets shoved to the extreme left of the page. I can work around it by putting the bracket in, say, \textrm{}, but I cannot figure out why it's happening.

[Johannes_B]

All those \items can have an optional argument. As you might already know, those are set within brackets. You already saw that by using braces, you can protect the brakets from being interpreted as the optional argument.
But why is there an optional argument? You can also see, that is messes up the numbering. But it's really useful using a description list. Please see below. You can click on »Open in writelatex« to see the output.

Code: Select all

\documentclass{article}
\usepackage{blindtext}
\usepackage{scrextend}%Just for labeling
\usepackage{showframe}
\begin{document}

\begin{enumerate}%[a.]
\item Whatever1 \blindtext
\item [Whatever2] \blindtext
\item {[Whatever3]} \blindtext
\end{enumerate}
\clearpage
\begin{description}%[a.]
\item empty no headers or footers
\item [plain] no header
\item {[headings]} header and footer
\end{description}
\begin{description}%[a.]
	\item [empty] no headers or footers
\item [plain] no header
\item [headings] header and footer
\end{description}
\begin{labeling}[~--]{headings}
	\item [empty] no headers or footers
\item [plain] no header
\item [headings] header and footer
\end{labeling}
\end{document}

[JasonM]

Thank you so much! I should have thought of that.