Comments Within Group Expressions

It is often useful to mix comments with names, particularly within a text file. All group expressions (whether obtained from the environment or from a text file or as an argument) are truncated if a ``comment'' character is found (usually `#'' but this can be changed, see section ). Anything occurring after such a character is ignored. In a text file, the comment is assumed to extend from the comment character to the end of the line, so a new group expression may be given on the next line. Note, blank lines are not ignored. Each blank line within a text file will result in a blank name being added to the group.