I have a few hundred contacts.
I want to start using the "User Field 4", say to store each contact's
country of citizenship.

Is there a way to select multiple records in a table view and automatically
assign a specific value (say "USA") for "User Field 4" in all selected
records?
I hate to believe that I have no other option but to change each record one
by one.

If you can help me with that, thank you very much, and please disrecard the
following.

Now if there is NO WAY to do what I want, is there how could I replace one
content with another in the "User Field 4" in all my contacts.
Indeed, if I must update each record one by one, I would rather use a
one-letter abbreviation for each country and then replace it on all the
records.
For example, I'd enter manually "U", "C", "K": and then change it to "USA",
"Canada" or "United Kingdom", respectively.

Thank you for reading so far, and for you help!

Wladimir