diff --git a/Configuration.md b/Configuration.md
index 1bc30bb..7fb7e16 100644
--- a/Configuration.md
+++ b/Configuration.md
@@ -130,6 +130,17 @@ the default upstreams, which should be specified as well.
 
 An empty domain specification, `//` has the special meaning of “unqualified
 names only”, i.e. names without any dots in them, like `myhost` or `router`.
+Those will only be used for resolving requests for unqualified domain names, but
+not their subdomains.  So, a configuration like this:
+
+```none
+5.6.7.8:53
+[//]4.3.2.1:53
+[/com/]1.2.3.4:53
+```
+
+sends requests for `com` (and its subdomains) to `1.2.3.4:53`, requests for
+other top-level domains to `4.3.2.1:53`, and all other requests to `5.6.7.8:53`.
 
 More specific domains take precedence over less specific domains.  So,
 a configuration like this:
@@ -164,7 +175,9 @@ specification for records' presence given in [RFC 4035, section
 
 For example, the `DS` query for `domain.example.com` will be sent to the
 upstream specified for `example.com`, `com`, or the default one, even if there
-is a more specific upstream like `*.example.com`.
+is a more specific upstream like `*.example.com`.  Note that for two-label `DS`
+requests, the upstream specified for unqualified names, or the more specific one
+will be used, if any.
 
 Since **v0.108.0-b.8** the wildcard `*` has a special meaning of "any
 subdomain", so `--upstream=[/*.host.com/]1.2.3.4` will send queries for