diff --git a/src/id_generation.rs b/src/id_generation.rs
index 65c0a5d..d8242a7 100644
--- a/src/id_generation.rs
+++ b/src/id_generation.rs
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: Apache-2.0
+// from https://github.com/jitsi/js-utils/blob/2fbf686ad94e72afbac0dbdb7d77b6c83e7a66c0/random/roomNameGenerator.js
+
 use std::collections::HashMap;
 
 use once_cell::sync::Lazy;