f Clarify `namespace`/`key` format requirments

diff --git a/lightning/src/util/persist.rs b/lightning/src/util/persist.rs
index 1597258e3608e909d3b1f38f3a40f155ae2a424c..ef4f84cb57e482722dfadaf18dff634e56ca8f0e 100644 (file)
--- a/lightning/src/util/persist.rs
+++ b/lightning/src/util/persist.rs
@@ -51,8 +51,8 @@ pub const SCORER_PERSISTENCE_KEY: &str = "scorer";
 /// Implementations of this trait are free to handle them in different ways, as long as
 /// per-namespace key uniqueness is asserted.
 ///
-/// Keys and namespaces are required to be valid ASCII strings and the empty namespace (`""`) is
-/// assumed to be valid namespace.
+/// Keys and namespaces are required to be valid ASCII strings that do not contain control
+/// characters, and the empty namespace (`""`) is assumed to be a valid namespace.
 pub trait KVStore {
        /// A reader as returned by [`Self::read`].
        type Reader: io::Read;