-defined type, or a hash of `parameter => value` pairs to be passed to `apt::key`'s `id`, `server`, `content`, `source`, and/or
-`options` parameters.
+defined type, or a hash of `parameter => value` pairs to be passed to `apt::key`'s `id`, `server`, `content`, `source`, `weak_ssl`,
+and/or `options` parameters.
+
+Default value: ``undef``
+
+##### <a name="keyring"></a>`keyring`
+
+Data type: `Optional[Stdlib::AbsolutePath]`
+
+Absolute path to a file containing the PGP keyring used to sign this repository. Value is used to set signed-by on the source entry.
+See https://wiki.debian.org/DebianRepository/UseThirdParty for details.