Dear maintainer(s), I noticed that package tk-brief recommends xpdf-reader, which is not available in unstable. I've checked the source of tk-brief (file /usr/bin/tk-brief) and I don't see it trying to use any binary named xpdf-reader itself, but tries to use "xdg-open" I guess that with a PDF file. I think that a good recommends might be "xpdf | pdf-viewer" (so, a basic concrete package to open PDFs and the virtual package pdf-viewer for people who already have a favourite PDF viewer). Thank you for your time, PS[0]: I am developing a tool to detect such issues: https://salsa.debian.org/carlespina/check-relations . Reports are manually reviewed before submission. If you would prefer not to receive such reports (for specific packages, all of your maintained packages, etc.), please let me know. Any other feedback is welcomed as well. No more bugreports for this missing relation will be sent. PS[1]: more information available in https://salsa.debian.org/carlespina/check-relations/-/blob/main/README.md and https://salsa.debian.org/carlespina/check-relations/-/blob/main/docs/bug-report-extra-info.md