"A writing system is wider than a spelling system. English uses many w:Logogramslogograms which have as unambiguous correspondence with a single morpheme but give no indications of pronunciations:1,2,3 etc, L, @, &, %, +. Many more are in use in mathematics and formal logic. Other specialized uses include proofreading symbols (e.g. for delete, insert). Many of these symbols are not specific to English, and more detailed discussion would shade off into special purpose writing systems such as shorthands and scientific notations. However, “normal” uses of English also include a wide range of such forms."