diff --git a/bstrlib.txt b/bstrlib.txt
index eacf7c7419cb5a03b904f825211c5a941482605c_YnN0cmxpYi50eHQ=..fac0cbbdf3cb0973782a41669150019cf07d9beb_YnN0cmxpYi50eHQ= 100644
--- a/bstrlib.txt
+++ b/bstrlib.txt
@@ -3448,6 +3448,14 @@
 committed to Unicode representation of its string data, and therefore cannot
 be used as a generic buffer library.
 
+SDS
+---
+
+Sds uses a strategy very similar to Libsrt.  However, it uses some dynamic
+headers to decrease the overhead for very small strings.  This requires an
+extra switch statement for access to each string attribute.  The source code
+appears to use gcc/clang extensions, and thus it is not portable.
+
 ===============================================================================
 
 Examples