This dialing format uses only numeric digits to identify a telephone destination. It replaced older systems that used the first two or three letters of a local exchange name followed by digits. The shift to pure numeric dialing allowed for a much larger pool of available phone numbers and standardized international dialing formats across different switchboards.
Heard on the job
We need to update the legacy database to ensure every entry is a valid all-figure number before the migration.
Insider tip
The transition to this format caused significant public pushback, as people felt numeric strings were harder to memorize than familiar neighborhood exchange names like PEnnsylvania 6.