release notes: document interactions between separateDebugInfo and ref blacklisting

doc/release-notes/rl-2511.section.md

@@ -19,6 +19,8 @@
 - `gentium` package now provides `Gentium-*.ttf` files, and not `GentiumPlus-*.ttf` files like before. The font identifiers `Gentium Plus*` are available in the `gentium-plus` package, and if you want to use the more recently updated package `gentium` [by sil](https://software.sil.org/gentium/), you should update your configuration files to use the `Gentium` font identifier.
 - `space-orbit` package has been removed due to lack of upstream maintenance. Debian upstream stopped tracking it in 2011.
 
+- Derivations setting both `separateDebugInfo` and one of `allowedReferences`, `allowedRequistes`, `disallowedReferences` or `disallowedRequisites` must now set `__structuredAttrs` to `true`. The effect of reference whitelisting or blacklisting will be disabled on the `debug` output created by `separateDebugInfo`.
+
 - `gnome-keyring` no longer ships with an SSH agent anymore because it has been deprecated upstream. You should use `gcr_4` instead, which provides the same features. More information on why this was done can be found on [the relevant GCR upstream PR](https://gitlab.gnome.org/GNOME/gcr/-/merge_requests/67).
 
 ## Other Notable Changes {#sec-nixpkgs-release-25.11-notable-changes}