Handling warnings

Warning messages are for your information. They don't always point to a severe problem, but often it's a good idea to read these tips carefully and act accordingly. This may improve your document.

We will test this now. Let's say we want to emphasize text that is in a sans-serif font. We expect italic sans-serif text as a result.

Let's try this:

1. Take our "Hello world!" example and modify it this way:

   \documentclass{article}
   \renewcommand{\familydefault}{\sfdefault}
   \begin{document}
   \emph{Hello world!}
   \end{document}

2. Compile. LaTeX will print out a warning in the log file:

   LaTeX Font Warning: Font shape `OT1/cmss/m/it' in size <10> not available
   (Font) Font shape `OT1/cmss/m/sl' tried instead on input line 4.

3. Check the output:

Figure 13.4 – Slanted shape instead of italic shape

The \familydefault macro stands for the default font family used in the LaTeX document...