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<style>
#point:after{
content:"\0211C";
}
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<body>
<p>Uppercase R Black Letter Capital using Hexa Decimal: ℜ</p>
<p>Uppercase R Black Letter Capital using HTML Code: ℜ</p>
<p>Uppercase R Black Letter Capital using HTML Entity: ℜ
</p>
<p id="point">Uppercase R Black Letter Capital using CSS Entity: </p>
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