4.1.6 Preprocessors in man pages

If a preprocessor like gtbl or geqn is needed, it has become common usage to make the first line of the man page look like this:

'\" word

Note the single space character after the double quote. word consists of letters for the needed preprocessors: ‘e’ for geqn, ‘r’ for grefer, ‘t’ for gtbl. Modern implementations of the man program read this first line and automatically call the right preprocessor(s).