Generally, an imported contact is considered to "match" an existing contact if they have the same name. The only exception to this is if you have previously exported your contacts using the native format.
If there is a match, but the two versions do not contain any conflicting information then the import operation will simply add any additional details from the imported version of the contact to the existing version.
This feature allows you to export your contacts as a CSV text file. This is useful if you wish to import your contacts into another application such as Microsoft Outlook or Outlook Express.
Note that the exported data does not include any information about what contact groups the contacts may belong to.
In native format, each exported contact list entry also includes a unique numerical identifier. If a CSV file containing such identifiers is subsequently re-imported, then contacts in the CSV file are considered to match entries in the contact list if their numerical identifiers match; matching is done on the basis of this identifier in preference to using the contact name.
This is valuable if, for example, you wish to export your contacts to a spreadsheet, make a set of changes and then re-import them - even if you change a contact's name, it will still be correctly correlated with the existing contact list entry.
Extensions allow you to quickly dial other numbers in the Business Group.
Short codes allow you to quickly dial common numbers.