This page ensures that WebKit can render unicode variation selector correctly. On platforms which support UVSes, the glyph of U+0061 should be a 0.2em high, 1em wide rectangle. On platforms which don't support UVSes, it should be a square. In addition, any glyphs (including the last resort glyph) should not appear after the glyph on all platforms.

Without UVS: X should look like X

With UVS: p should look like p

UVS not in the font should fallback to base: X should look like X