diff --git a/src/cfgfile.c b/src/cfgfile.c
index 8d3139bb..e4b1db16 100644
--- a/src/cfgfile.c
+++ b/src/cfgfile.c
@@ -156,6 +156,8 @@ operation_mode config_str_to_omode(const char *str)
         return OMODE_NORMAL;
     } else if (strcasecmp(str, "legacy-compat") == 0 || strcasecmp(str, "legacy") == 0) {
         return OMODE_LEGACY;
+    } else if (strcasecmp(str, "strict") == 0) {
+        return OMODE_STRICT;
     } else {
         ICECAST_LOG_ERROR("Unknown operation mode \"%s\", falling back to DEFAULT.", str);
         return OMODE_DEFAULT;
diff --git a/src/cfgfile.h b/src/cfgfile.h
index 3fa3336e..93d6e9ff 100644
--- a/src/cfgfile.h
+++ b/src/cfgfile.h
@@ -33,9 +33,24 @@ struct _mount_proxy;
 #define XMLSTR(str) ((xmlChar *)(str)) 
 
 typedef enum _operation_mode {
+ /* Default operation mode. may depend on context */
  OMODE_DEFAULT = 0,
+ /* The normal mode. */
  OMODE_NORMAL,
- OMODE_LEGACY
+ /* Mimic some of the behavior of older versions.
+  * This mode should only be used in transition to normal mode,
+  * e.g. to give some clients time to upgrade to new API.
+  */
+ OMODE_LEGACY,
+ /* The struct mode includes some behavior for future versions
+  * that can for some reason not yet be used in the normal mode
+  * e.g. because it may break interfaces in some way.
+  * New applications should test against this mode and developer
+  * of software interacting with Icecast on an API level should
+  * have a look for strict mode behavior to avoid random breakage
+  * with newer versions of Icecast.
+  */
+ OMODE_STRICT
 } operation_mode;
 
 typedef enum _http_header_type {