Que signifie l’erreur « Entering compatibility mode »?

  • Message: Entering compatibility mode

  • Origine: LaTeX.

You run your LaTeX job, and it starts by saying


followed by lines of asterisks and !!WARNING!!.

This means that the document is not written in « current » LaTeX syntax, and that there is no guarantee that all parts of the document will be formatted correctly.

If the document is someone else’s, and you want no more than a copy to read, ignore the error. The document may fail elsewhere, but as often as not it will provide a dvi or pdf that’s adequate for most purposes.

If it’s a new document you have just started working on, you have been misled by someone. You have written something like:


or, more generally:


These forms are (as the warning says) LaTeX 2.09 syntax, and to get rid of the warning, you must change the command.

The simple form is easy to deal with:


should become:


The complex form is more difficult, since LaTeX 2.09 « options » conflate two sorts of things — options for the class (such as 11pt, fleqn), and packages to be loaded. So:


should become:


because 11pt happens to be a class option, while verbatim is a package.

There’s no simple way to work out what are class options under LaTeX 2.09; for article, the list includes 10pt, 11pt, 12pt, draft, fleqn, leqno, twocolumn and twoside — anything else must be a package.

Your document may well « just work » after changes like those above; if not, you should think through what you’re trying to do, and consult documentation on how to do it — there are lots of free tutorials to help you on your way, if you don’t have access to a LaTeX manual of any sort.

Source: Entering compatibility mode