\hyphenation{words}
The \hyphenation command declares allowed hyphenation points, where words is a list of words, separated by spaces, in which each hyphenation point is indicated by a - character. For example
\hyphenation{fortran,er-go-no-mic}indicates that "fortran" cannot be hyphenated and indicates allowed hyphenation points for "ergonomic".
This argument to this command should contain words composed only of normal letters. To suggest hyphenation points for strings containing nonletters or accented letters, use the \- command in the input text.
This command is normally given in the preamble.