The icon is only shown for activities that are summary data only because they were recorded on a different unit and sent over via the true-up mechanism.
If the activity was recorded on the unit and you have the full ride data there then it will not have a sport specific icon next to it.
aweatherall : Thank you very much for that information. On looking at the dates on my device it is obvious that the ones with the icon were actually recorded via my mobile phone, before I had got the Garmin up and running. The Garmin is a terrific piece of kit but I do wish that for something so expensive Garmin would provide a much better instruction book. I suppose the same could be said about most bits of computer based kit one buys these days. Anyway, thanks again. You and the Forum have worked well for me and I am sure to be using it again. Allen