The "add a Y to initials" idea is brilliant.

Now we have three methods:

1. John William Smith > JWS
2. John William Smith > JSW
3. John Smith in Canada > YJS

To the great dismay of our example John, he has no airport under any of these methods.

I just found out that YTR is Trenton, Ontario, Canada.

So now I got Trenton, Ramadan and Oslo.

Till