HTML ASCII Character References
Using &#x formatting to show the ASCII characters
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Character Reversal
Reformatting words by displaying them RTL
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Element rotation
Rotating HTML elements to show them in a different order
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Malformed tags
Unclosed and incorrectly terminated HTML tags
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Unicode lookalikes
Unicode characters that look like the characters you know and love, but actually aren't
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Playing with spacing
Inserting different spacing characters that make it non-obvious where a "real" space occurs
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