The New Bulletproof Font-Face Syntax | Fontspring
In September 2009, Paul Irish came up with the Bulletproof syntax for writing the font-face declaration. It was compact and worked across all browsers at the time. Recent, growing complaints that fonts weren’t loading in Android, led us to recommended the Mo’ Bulletproofer syntax devised by Richard Fink instead. Unfortunately Mo’ Bulletproofer requires double declarations and is therefore harder to maintain.