Uniform number (American football) - Wikipedia
NFL jersey number restrictions could change for running backs
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Eagles unveil jersey numbers; D'Andre Swift to wear No. 0
NFL players can now wear No. 0 among rule changes
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NFL Relaxes Restrictions on Jersey Numbers - The New York Times
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NFL won't fine players who wore 9/11 tribute cleats
9 NFL players who should wear 0 on their jersey immediately
NFL Allowing Players To Wear Number 0 For First Time Ever
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