Function math_italic_encode 

pub fn math_italic_encode(payload: &str) -> String

Mathematical Italic alphabet — same NFKC trick as math_bold_encode but in a different Unicode block (U+1D434 uppercase, U+1D44E lowercase). WAFs that have added detection for the bold range (U+1D400-) do not always cover italic.

One subtle gap: the math-italic block has a HOLE at U+1D455 where ‘h’ would have been (the letter ‘h’ was unified with U+210E PLANCK CONSTANT in an earlier Unicode revision). We substitute U+210E so the round-trip stays NFKC-correct.

Reference: https://ibrahimsql.com/posts/waf-bypass-unicode