The training runs will show as 5Zxx in detailed view.331 training and a couple of daytime stunts via Broughton Rd
I think the OP was referring to workings that started and finished at Brouhton Road. I have a feeling they show up as Skipton to Skipton at other stations in some cases, or used to.I couldn’t find any services that ran Skipton to Skipton but there are numerous Skipton to Skipton Broughton CS, is that what you mean?
If so these are extensive carriage sidings just north of the station capable of storing up to 14 units, and as far as I am aware have carriage cleaning facilities and toilet discharge points.