Frequently Asked Question List for TeX

# Improper `\hyphenation` will be flushed

For example

``````! Improper \hyphenation will be flushed.
\'#1->{
\accent 19 #1}
<*> \hyphenation{Ji-m\'e
-nez}
``````

(in Plain TeX) or

``````! Improper \hyphenation will be flushed.
\leavevmode ->\unhbox
\voidb@x
<*> \hyphenation{Ji-m\'e
-nez}
``````

in LaTeX.

As mentioned in “hyphenation failures”, “words” containing `\accent` commands may not be hyphenated. As a result, any such word is deemed improper in a `\hyphenation` command.

Hyphenation happens as paragraphs are laid out; by this time, TeX knows what font is used for each glyph; thus it knows the encoding being used. So the solution to the problem is to use a font that contains the accented character; doing this this “hides” the accent from the hyphenation mechanisms.

For LaTeX users, this is quite an easy task; they select an 8-bit font with the package, as in `\usepackage[T1]{fontenc}`, and accented-letter commands such as the `\'e` in `\hyphenation{Ji-m\'e-nez}` automatically become the single accented character by the time the hyphenation gets to look at it.