Since we pretty much made them up as we went along to fit different circumstances, we describe them as we go along, too. In general, though, the names of files and UNIX utilities are printed in
italics
, the names of Perl functions, operators, and other keywords of the language are in
bold
, and examples or fragments of Perl code are in
constant width
, and generic code terms for which you must substitute particular values are in
italic constant width
. Data values are represented by
constant width
in roman quotes, which are not part of the value.