Unicode has a Pc category into which it assigns various low lines:
_ U+005F LOW LINE ‿ U+203F UNDERTIE ⁀ U+2040 CHARACTER TIE ⁔ U+2054 INVERTED UNDERTIE ︳ U+FE33 PRESENTATION FORM FOR VERTICAL LOW LINE ︴ U+FE34 PRESENTATION FORM FOR VERTICAL WAVY LOW LINE ﹍ U+FE4D DASHED LOW LINE ﹎ U+FE4E CENTRELINE LOW LINE ﹏ U+FE4F WAVY LOW LINE ＿ U+FF3F FULLWIDTH LOW LINE However, the overlines that are almost exactly the same thing, are categorized as Po: ‾ U+203E OVERLINE ﹉ U+FE49 DASHED OVERLINE ﹊ U+FE4A CENTRELINE OVERLINE ﹋ U+FE4B WAVY OVERLINE ﹌ U+FE4C DOUBLE WAVY OVERLINE Is this a bug or a feature? :) Shouldn't they be Pc? ~fantasai
