On Tue, 30 Dec 2025, David Wright wrote:
These references may help: https://wiki.debian.org/SourcesList ? https://www.debian.org/mirror/ftpmirror
It is supported by buster, and even stretch. You have to go all the way back to jessie for it not to be supported.? Note that there's a new format for sources files, variously called debian.sources, deb822, or Debian RFC822 format, not supported by buster, and recommended for trixie on. (It's in the wiki.)
What is new -and I don't know when it was added, is Signed-By. I think that might work from stretch too but I didn't know of it until trixie so I've not used it yet.