It is a British English word, it isn't well known in the US , and judging by the other comments it isn't known in most of the colonies. It is only known to me because I have watched thousands of hours of British TV. On that basis I can very confidently say to just use whatever names you like. That type of person doesn't have a particular type of name. A diminutive form of the name would be better. ( meaning instead of "Rick" , use "Ricky" instead of " John" use "Johnny" ""Jessica" should be "Jess" or "Jessy" )
(edited to complete the last sentence)