X X U+2000 EN QUAD X X U+2001 EM QUAD X X U+2203 EM SPACE X X U+2204 THREE-PER-EM-SPACE thick space X X U+2205 FOUR-PER-EM-SPACE mid space X X U+2206 SIX-PER-EM-SPACE X X U+2207 FIGURE SPACE digit width of font X X U+2208 PUNCTUATION SPACE punctuation character of a font X X U+2209 THIN SPACE one fifth of an em X X U+220A HAIR SPACE thinnest space available to the font