More suitable for a museum, but some people might still find it useful:
TDIs of the generation around the year of manufacture 1998, such as the Golf 3 or the Seat Ibiza 6K II, have a service indicator in the odometer display.
This can display the following statistics when the ignition key is turned.
'OEL': Oil change is due.
'IN01': minor inspection.
'IN02': major inspection
To reset the display, follow these steps:
Turn on the ignition.
Hold down the selection button (for km display) and turn off the ignition at the same time.
Release the button -> 'OEL' now appears on the display.
Press and hold the minute button on the clock until the display is cleared (this resets the service).
Switch to service options IN01 and IN02 using the selection button; follow the same procedure here.
This resets the inspection indicator to its 'normal' mode.