Yorkshire Diesel Running

Hi there,

Currently planning one of my yearly trips to Yorkshire, 2nd June - 5th June 2012, I plan on avoiding Railfest, except for the Deltic Tour, to enjoy Yorkshires other railway attractions, looking at the NYMR timetable, it notes that 'S' symbolizes Steam Hauled Trains, and 'D' symbolizing Diesel, but what about the trains that have no symbol?

http://www.nymr.co.uk/timetables-and-fares/timetable/

Also at Keighley, I wish I could come up the week before for the Diesel Gala, alas I cannot, and assume that the Summer Morning runs are undertaken by the Railcar? unless someone can correct me on that :)