Hi again Sam,
We use the same system for call
sign numbers as the Alfa Tango group :-
Alfa Tango Prefix List
So in your instance the first digit '2' is for the U.S.A. and in my own '26' is for England.
CT is obviously Charlie Tango and then you are member number '239' in your division.
It would be easy for anyone to find out what country you heralded from on a DX call
and the Charlie Tango site is very easy to find also where they could confirm your membership and even contact you for further details such as for a QSL.
On my own links here (under my postings) I have my email address as well as my 'www' address which points to my QRZ page for my Ham radio call
sign. (You can add or specify different locations by clicking the 'Profile' button at the top of the website when you are logged in and edit your own profile.)
All handy stuff and completely free....Radio Enthusiasts helping fellow Radio Enthusiasts.
Hope that helps.