Rich,
If you look on the chart you will see 3 symbols in front of D026. A quick look at the legend will inform you that one symbol tells you that you can phone Plymouth Ops before take off; another tells you that London Information will provide an activity information service over the radio.
You may also find ENR 5-1 &
ENR 6-5-1-1 useful.
There are indeed phone numbers for a lot of them but they can be hard to dig out
As well as being in the AIP they are written on the flipping chart!