The first ever Formula 1 Grand Prix was held in India the weekend of 28-30 October, 2011.
To mark this event, Indian radio amateurs were authorised to append "/F1" to their callsigns, from 26-31 October, 2011.

Club Log has a special rule to implement this, so that Indian callsigns with /F1 are mapped to India, and not France, in that period.
Callsign exceptions are not required by Club Log for these callsigns.