Attached to the Guardian story Russia warns of nuclear weapons in Baltic if Sweden and Finland join Nato, the paper posted a correction:
This article was amended on 15 April 2022 to better characterise Kaliningrad as an exclave, rather than an enclave.
This Wikipedia page proved helpful in understanding the difference: Kaliningrad is an exclave because it’s a part of Russia geographically separated from the rest of the country. Vatican City, by contrast, is completely surrounded by Italy, and is thus an enclave.
The article is required reading for any student of geographic edge cases.