diff --git a/loolwsd/LOOLProtocol.hpp b/loolwsd/LOOLProtocol.hpp
index 6120e0cb7..3857a4e86 100644
--- a/loolwsd/LOOLProtocol.hpp
+++ b/loolwsd/LOOLProtocol.hpp
@@ -133,7 +133,11 @@ namespace LOOLProtocol
         return getFirstLine(message.data(), message.size());
     }
 
-    /// Returns an abbereviation of the message (the first line, indicating truncation).
+    /// Returns an abbereviation of the message (the first line, indicating truncation). We assume
+    /// that it adhers to the LOOL protocol, i.e. that there is always a first (or only) line that
+    /// is in printable UTF-8. I.e. no encoding of binary bytes is done. The format of the result is
+    /// not guaranteed to be stable. It is to be used for logging purposes only, not for decoding
+    /// protocol frames.
     inline
     std::string getAbbreviatedMessage(const char *message, const int length)
     {