Double hyphen

It was a development of the earlier double oblique hyphen ⸗, which developed from a Central European variant of the virgule slash, originally a form of scratch comma.

In order to avoid it being confused with the equals sign =, the double hyphen is often shown as a double oblique hyphen in modern typography.

The double hyphen is also not to be confused with two consecutive hyphens (--), which are often used to represent an em dash — or en dash – due to the limitations of typewriters and keyboards that do not have distinct hyphen and dash keys.

The double hyphen is used for several different purposes throughout the world: When the double hyphen is used as a functionally equivalent graphical variant (allograph) of the single hyphen, it has the same Unicode code point as a conventional hyphen (since how it is displayed/printed is a font choice on that occasion).

Other forms of double hyphen are given unique codepoints in Unicode:

Double oblique hyphen in a Fraktur typeface

Double hyphen appearance in several Fraktur typefaces

Double oblique hyphens (besides ordinary hyphens) used in a Hittite dictionary ^{[

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Double (straight) hyphen in an edition of stories by Arno Schmidt ^{[

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