Query the Unicode property table with \p{L}, \p{N}, and \p{Script=Arabic}, predict what \w actually matches in a given engine, and reach for property escapes when ASCII assumptions break.

Type \w+ to grab a word and run it on café. In a browser's regex engine the match stops at caf, dropping the é on the floor, the same silent cut you would get on naïve or Zoë.

Match a whole user-visible character with \X when the dot would split it into codepoints, predict when two spellings of the same glyph fail a literal pattern, and normalize both sides before matching.

Run the pattern . against the accented à and the engine hands back a bare a, the accent left sitting in the string. One key on your keyboard, two numbers underneath, and the dot only ever takes one.