UK-02 Major Airport Codes
UK-02 Major Airport Names
I'd better elaborate on these files.
By default the airfield waypoint file provides both airfield name and ICAO code on screen (UK-02 Major Airport Names). For those who find this too intrusive I created a second file (UK-02 Major Airport Codes) which will only display the ICAO code. Use one or the other but not both.
You can optionally install both and then use the Data Files menu in BaseStation to turn on the file you need. I normally have codesonly on display but swap to the name and code file when taking screenshots.
Code only display: