What “valid number” really means
A pattern can fit a plan without belonging to an active subscriber.
Possible
The length and broad structure can be plausible.
Valid range
Metadata may say the range is assignable.
Reachable
Only a separate live verification can establish whether a service answers now.
Choose a status label with a defined test
These are hypothetical interface labels, not actual lookup results.
| Label | Required explanation |
|---|---|
| Prefix recognised | Which calling-code set was searched |
| Valid format | Which numbering metadata/version was applied |
| Active or reachable | What service was actually tested and when |
An interface should describe its test, not let a green checkmark stand in for several different claims.