Some glyphs intersect themselves in such a way that, at least in Chrome and Firefox, the overlaps appear white. Examples include U+0041 LATIN CAPITAL LETTER A, U+0472 CYRILLIC CAPITAL LETTER FITA, and U+0030 DIGIT ZERO with 'ss05'. Not all self-intersecting glyphs have this problem.
Some glyphs intersect themselves in such a way that, at least in Chrome and Firefox, the overlaps appear white. Examples include U+0041 LATIN CAPITAL LETTER A, U+0472 CYRILLIC CAPITAL LETTER FITA, and U+0030 DIGIT ZERO with 'ss05'. Not all self-intersecting glyphs have this problem.