Underful hbox badness 10000

Question

A while back I ran across a web page that explained how to avoid this error by not using \\ but hfill or hspace. I can't remember which one or find anything else about it. It was a very simple solution and solved the problem without extra packages or anything and simply filled the remaining horizontal space. Any ideas?

Answer 1

Although it is difficult to adequately reproduce this warning (not an error), you may be after the UK TeX FAQ entry No line here to end. Here is one such a reproduction of the warning:

\documentclass{article}
\begin{document}
\begin{description}
  \item[Very long label] Some starter text \\
    \\
    Here is some more text.
\end{description}
\end{document}

The problem stems from the use of \\ to insert a blank line. Rather use a vertical skip (like \smallskip, \medskip or \bigskip) or leave a blank line - that would indicate a paragraph break and an associated "blank line". Alternatively, a resolution suggested is to provide an infinite stretch of space \hspace*{\fill} so that there's enough "to go around" for TeX to fill the line before breaking it.