The underscore, another light character, replaced the asterisk above the hyphen. Use of a double hyphen instead of a solidus allows inclusion in computer filenames. The spelling now used is without a hyphen. The term may be spelled with or without a hyphen (antisemitism or anti-Semitism). Unicode distinguishes the hyphen from the general interpunct. This rule is known as the "LDH rule" (letters, digits, hyphen). Several regular symbols, such as * (asterisk), - (hyphen), . This gap can be transliterated with a hyphen . Given names are separated from surnames by a hyphen. In Germany a double surname () is generally joined with a single hyphen. The first known documentation of the hyphen is in the grammatical works of Dionysius Thrax. Its meaning is the same as a hyphen, as represented by the hyphen-minus glyph. He was sometimes credited without the hyphen in his surname. There is the possibility that one partner can combine both names by a hyphen. The numeral following the hyphen is the current rating of the device in amperes.