I corrected the subject...

Ross wrote:

I have a question regarding the rings shown on some charts and not
others. They are a dashed ring and are labeled "FEEDER FACILITIES"
and/or "ENROUTE FACILITIES". The may not be on all charts nor both on
the same chart. For example http://naco.faa.gov/d-tpp/0801/06000LD15.PDF.
I tried the Google route and that didn't work. I thought some of the ATC
folks could help me find out their meaning.

Ross
KSWI