Flexfields:Shorthand Entry profile option. What is the expected behaviour of a NULL value at site va

 None of the documentation I have read explains what the default (NULL) behaviour is intended to be with this profile option.  Can anyone advise?

(Asking because we are appearing to have some responsibilities in GL see the shorthand alias window, and others not.  (Seen from web ADI journal upload LOV search and select - and even though at site, application, organisation, responsibility of the connection, and user it can be shown to be null. )