An rpc file extension is related to the 3WayPack software. An rpc file contains data. Obsolete format.
RPC file extension - 3WayPack data
What is rpc file? How to open rpc files?
File type specification:
The rpc file extension is associated with the 3WayPack, a three-mode software and promoting three-mode data analysis developed by the Three-Mode Company.
3WayPack is obsolete product, but .rpc files created in it are stored in simple text file format and viewable in the text editors.
This rpc 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.