Recently a Fontdeck customer asked for help regarding a problem he was having with a soft hyphen. Our chief web typography evangelist, Richard Rutter, investigated further and uncovered a peculiar bug in Mac-based Webkit browsers, including Safari and Chrome. Fortunately Richard also found a workaround.
Soft hyphens enable you to manually insert hyphenation points in words. Thus a soft hyphen is a hyphen which is only displayed when a word is split across two lines. Put another way, the character says ‘hyphenate here if you need to’.
Richard has gone into lots of detail about the bug on his blog, but in summary under some circumstances, when using webfonts (any webfonts, not just Fontdeck) Mac Webkit browsers will display a missing glyph symbol where the soft hyphen is placed, for example:
To fix this, include Arial somewhere appropriate in your font stack, eg.
font-family: "Apercu Light", Helvetica, Arial, sans-serif.