glen
we had them on our hi charts too...but the chart it self explained what they were in the LEGEND. You may have to look closely.
I don't have one in front of me now and never used those routes, but suffice to say these were agreed upon routes between the company and ATC using available nav on our planes. Some were based on the low altitude structure, which can't be used in the high altitude structure.
(ie) too much distance between nav aids for altitude. sometimes we got a clearance that said: between x and y via the radials of Victor so and so
do look on the chart itself, all over and you may find the answer. sort of shortcuts.