Each feed is kept in separate subdirectory in the feeds/. Its name is not important, but human readable is a preferable choice. It contains:
File with the URL of the feed. This is the only file you have to manually deal with.
If may contain maximal number of messages per current feed to keep and process.
Those files are used by curl to keep the content, its proper
mtime (for If-Modified-Since header generation),
ETag and response headers for debugging.
It contains the content itself.
SHA-512 hash of the feed, used to determine if feed was updated and parser has to do the job.
Automatically generated file with the title of the feed.
Directories necessary for making the directory Maildir mailbox. They contain parsed news posts.
Optionally created directories for storing of downloaded enclosures and WARCs.