It doesn't seem that is possible to convert Nokia audio (.rel) to a Symbian OS contact database (.cdb), which is what rel to cdb conversion would represent. If you are looking for something or know anything useful about how to convert rel to cdb, please leave us a message in the discussion below.
This conversion entry was verified by us and conversion was flagged as wrong or not possible.
Usually this happens when the conversion would try to convert different types of data between each other, such as audio to image, or it is not possible because incompatibility between programs, caused by closed file formats, very limited support etc.
If you find entry that you feel is flagged as bad wrongly, please tell us in the discussion below with as much as information as possible so we can fix it.