Index: generic/xotcl.h
===================================================================
diff -u -ra6087540279fa5a9110728605795620ecd43e10e -rf71845baf5b995318b585981109bdf114d95eb2f
--- generic/xotcl.h	(.../xotcl.h)	(revision a6087540279fa5a9110728605795620ecd43e10e)
+++ generic/xotcl.h	(.../xotcl.h)	(revision f71845baf5b995318b585981109bdf114d95eb2f)
@@ -76,12 +76,15 @@
 #define CONFIGURE_ARGS_TRACE 1
 */
 
-/*
+/* some features
 #define TCL85STACK 1
 #define CANONICAL_ARGS 1
 */
+
+#if !defined(PRE86)
 #define CANONICAL_ARGS 1
 #define TCL85STACK 1
+#endif
 
 #if defined(PARSE_TRACE_FULL)
 # define PARSE_TRACE 1
@@ -117,6 +120,17 @@
 # define PRE85
 #endif
 
+#if TCL_MAJOR_VERSION==8 && TCL_MINOR_VERSION<6
+# define PRE86
+#endif
+
+#if defined(PRE86)
+# define CONST86
+# else
+/*#  define NRE*/
+#endif
+
+
 #if !defined(FORWARD_COMPATIBLE)
 # if defined(PRE85)
 #  define FORWARD_COMPATIBLE 1