To support DXCC features XMLog needs to be able to associate callsigns with DXCC countries. XMLog assigns a "main" prefix to each DXCC country to uniquely identify it. This prefix is used in summaries, reports, PacketCluster alerts, and in the "Prefix" field of log entries.
The file "prefixes" defines these main prefixes as well as other prefixes that are associated with each country. This file also contains other information such as the latitude, longitude and zone. DXCC country associations for specific callsigns are maintained elsewhere (see The Callsign List).
From time to time countries are added or deleted from the official DXCC list. The version of XMLog available at www.xmlog.com should have an up-to-date prefixes file so the easiest way to maintain a current DXCC country list is to install the latest version of XMLog.
Occasionally the DXCC prefix for a country is changed - for example many ex-USSR countries received new prefixes in 1994. When a new version of XMLog is installed that contains changes to any prefixes your log file will automatically be updated and a list of changed prefixes will be displayed.
Edit/Change Prefix for Multiple Entries allows you to change the prefix for all entries in your log or every occurrence within the "currently selected" entries. This can be useful when importing old logs that don't contain DXCC country information - XMLog's country guesses may not be accurate for countries that have had their prefixes changed or counties that have had their DXCC status changed to "deleted". See the Deleted Countries section of Importing and Exporting Log Entries for some examples.