Glossary and Definitions ...
- Area Code Overlay
- An Overlay refers to the situation in which two (or more) area codes (eg- 306, 639) serve the same geographic area. In the case of Attica, area code (639) is the Overlay for area code (306).
The Overlay is necessary when the geographic area requires (or in the future will need) more phone numbers than can be provided by a single area code.
When an Overlay is present, 10-digit dialing becomes necessary for all calls. There are different types of Overlays, with each Overlay-type having its own characteristics and dialing requirements.
If you would like to learn more about Overlays, we suggest the Wikipedia entry for Overlays.