diff --git a/bstrlib.h b/bstrlib.h
index fac0cbbdf3cb0973782a41669150019cf07d9beb_YnN0cmxpYi5o..8e433874f57efbe91fef837464eae520f43ed7e7_YnN0cmxpYi5o 100644
--- a/bstrlib.h
+++ b/bstrlib.h
@@ -36,6 +36,11 @@
 typedef struct tagbstring * bstring;
 typedef const struct tagbstring * const_bstring;
 
+/* Version */
+#define BSTR_VER_MAJOR  1
+#define BSTR_VER_MINOR  0
+#define BSTR_VER_UPDATE 0
+
 /* Copy functions */
 #define cstr2bstr bfromcstr
 extern bstring bfromcstr (const char * str);
diff --git a/bstrlib.txt b/bstrlib.txt
index fac0cbbdf3cb0973782a41669150019cf07d9beb_YnN0cmxpYi50eHQ=..8e433874f57efbe91fef837464eae520f43ed7e7_YnN0cmxpYi50eHQ= 100644
--- a/bstrlib.txt
+++ b/bstrlib.txt
@@ -593,6 +593,33 @@
 that use bstrings or CBStrings including bstrlib.c, bstraux.c and
 bstrwrap.cpp.
 
+Version
+-------
+
+v1.0.0
+
+
+The version format v[Major].[Minor].[Update] is used to facilitate
+developers with backward compatibility in the core developer branch of the
+Better String Library.  This is also reflected in the macro symbols
+BSTR_VER_MAJOR, BSTR_VER_MINOR and BSTR_VER_UPDATE in the bstrlib.h file.
+Differences in the Major version imply that there has been a change in the
+API, and that a recompile and usage source changes may be necessary.
+Differences in Minor version imply that there has been an expansion of the
+API, that backward compatibility should be preserved and that at most a
+recompile is necessary (unless there is a namespace collision).  Differences
+in Update imply that no API change has occurred.
+
+Although ordered, there is no implication of lexical sequencing.  In
+particular, the Update number will not reset to 0 as the Major and Minor
+version numbers increment.
+
+So simple bug fixes will usually be reflected in a change in the Update
+number.  If new functions are available, the Minor value will increment.
+If any function changes its parameters, or if a function is removed, the
+Major value will increment.
+
+
 ===============================================================================
 
 Files