All values in the file are CreatureDef IDs of the player character.
The first value in a line is the CDefID of the source player character.
The remaining comma separated values on the line are CDefIDs of other player characters who are assigned as friends to the source character.
The total list of friends can be spread out along multiple lines as long as the source CDefID is the same. For readability, the server limits output to 10 friends per line.