/^(([A-Z][A-Z]{0,1})([0-9][A-Z…

/^(([A-Z][A-Z]{0,1})([0-9][A-Z0-9]{0,1})) {0,}(([0-9])([A-Z]{2}))$/i

Go Haskell Java JavaScript .Net Perl PHP PostgreSQL Python Ruby Tcl XRegExp

https://www.regexplanet.com/share/index.html?share=yyyyf8tmb3r