| File identifiers

| These will be checked if a file's mode (see Types*) is specified as "Text".
| Zap regular expressions are used.

| The expressions are tested against the first (non-blank) line, provided
| that it is within the first 1K of the file, and, to succeed, must match to
| the end of that line (not including the \n).

| Example:
|2100	Perl		\<#! \*/usr/\(local/\|\)bin/perl\( \.\%\|\)

