(Ross Oliver) writes:

The legend on the chart says: "Services - fuel available and field tended
during normal working hours..." No mention of maintenance facilities. For
example, the Byron airport (C83) according to the AOPA airport directory has
fuel but no maintenance, and that airport is depicted with tick marks.

The NACO Aeronautical Chart User's Guide
(http://www.naco.faa.gov/index.asp?xml=naco/catalog/charts/supplementary/aero_guide)
is kind of vague, but seems to say ticks indicate "Refueling and repair
facilities for normal traffic."

Dan.