External rules

External phone numbers:
If a telephone system is used, a difference must be made between internal and external phone numbers. Normally, internal phone numbers are recognized based on the extension range and the length of an internal phone number that has been configured for the telephone system. Deviating from this, it may be necessary to classify certain numbers that would normally be understood as internal phone numbers as external phone numbers.

The rules permit detection of phone numbers based on Regular Expressions or direct comparison. Each entry can be configured individually. If the Replace With column has been entered, the phone number will be replaced automatically. Subsequently, the phone numbers will not be formatted further, but should however be transferred in international format. The configured rules will be processed from top to bottom, until a match has been found.

Check:
The rules can be checked immediately. Enter the corresponding expression in the Phone Number field. If the phone number was detected and how it has been implemented can be seen in the output row. The rule used for recognizing and formatting will be highlighted.

	Specific Examples for the Use of Special External Rules: Detection of external phone numbers that would normally be understood as internal phone numbers (emergency numbers that are within the internal phone number range, but have not been assigned an extension (110, 112 and 911).
	If a comprehensive set of rules should be established, the list can be maintained outside the administrator's utility. Existing rules can be exported as XML or CSV files, adjusted correspondingly and then re-imported.