Files with rdr file extension can be mostly encountered as report files from an old program called Dynamic Report Decoder.
There is one other file type using
the RDR file extension!
.rdr - Remote Desktop Manager report settings
RDR file extension - Dynamic Report Decoder report
What is rdr file? How to open rdr files?
File type specification:
The rdr file extension seems to have been in the past used in a program called Ryder Dynamic Report Decoder, which seems to have been discontinued years ago.
The rdr file from this application contains some sort of export.
This rdr file type entry was marked as obsolete and no longer supported file format.
This type of file is no longer actively used and is most likely obsolete. This is typically the case for system files in old operating systems, file types from long discontinued software, or previous versions of certain file types (like documents, projects etc.) that were replaced in higher versions of their original programs.