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.