The various uses of the present symbol derive from several sources. The medieval virgule (Latinvirgula) was an oblique or vertical line that served as a comma, period, and caesura mark and is still used in literary contexts for the slash marking line breaks. (This mark separately developed as the comma ⟨,⟩ and caesura mark ⟨‖⟩ and some senses of the vertical bar ⟨|⟩.) The shilling mark (Latinsolidus) was variously written s. or as the long sſ. This eventually developed into a single unpunctuated slash; its use to separate shillings from pence was sometimes generalized to any currency division. Most mathematical senses derived from the earlier horizontal fraction bar (as in 12), rewritten with a slash by the 18th century to permit fractions to be written on a single line. As a separator and conjunction, it represents an oblique form of the dash ⟨–⟩ or hyphen ⟨-⟩. Its use to mark supposed actions derives from command formatting in online chat forums, while its use to comment on preceding text derives from its use in some programming languages to form closing tags. Its present British name stroke derives from its use in telegraphy; its present American name slash gained wide currency from its use in computing.
Various uses may simply be read out, as "even" for currency or "out of" for totals, or generally left unspoken, as with line breaks and date separations.
The mark itself was originally known as the virgula or virgule in its medieval use as a form of period or comma. It is now defined by Unicode and ISO as the solidus, a late-19th-century British term for the shilling mark. (Some typographers mistaken label this mark as the virgule and distinguish the solidus as the fraction slash ⟨⁄⟩, but neither historical nor present official use supports such a distinction.) Now generally known by the American term slash, although still frequently known as a stroke in British English. For translations and less common English names, see slash.