A .flow file extension is related to the FLOW structured data definition file format.
FLOW file extension - FLOW structured data definition
What is flow file? How to open flow files?
File type specification:
The flow file extension is associated with the FLOW, a file format format used to store, retrieve and transmit structured data, developed by the ontonym.net.
The .flow files are stored in simple text format and viewable in a text editor.
This flow 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.