The
slashed zero is a representation of the number '
0' (zero), with a
slash through it. The slashed zero glyph is often used to distinguish the digit "zero" ("0") from the
Latin script letter "O" anywhere that the distinction needs emphasis, particularly in
encoding systems, scientific and engineering applications,
computer programming (such as
software development), and telecommunications. It thus helps to differentiate characters that would otherwise be
homoglyphs. It was commonly used during the
punched card era, when programs were typically written out by hand, to avoid ambiguity when the character was later typed on a
card punch.