Our settings framework supports "wildcards" to hide regular expressions from users. It is used in http proxy and fact/nic exclude filters. See self.convert_array_to_regexp and self.regexp_expand_wildcard_string methods from Setting model.

A customer has RHV/oVirt hypervisors with thousands of interfaces named on86bb6c1f143a4.3111 and since "on*" is too broad, a support for "?" would enable them to do "on?????????????.*" wildcard to match those NICs.