Special characters in wifi password

Special characters are not allowed in WiFi password. Is this a bug or a feature? I can see a few people have had issues with this.

At the moment, it’s a feature (meaning it’s not going to get a whack of attention).
Annoying - yes, life threatening - not so much.

Guessing that part of that limitation comes from the library we have to live with to get WiFi and a web page into an ESP.