+const static char* FEATURE_NESTED = "nested";
+const static char* FEATURE_INTERNAL = "internal";
+const static char* FEATURE_OBLIGATORY = "obligatory";
+// TODO: Rename
+const static char* PREVIOUS_FEATURE_PARAM = "previous_feature_param";
+const static char* ANY_WDG_TOOLTIP = FEATURE_TOOLTIP;
+const static char* ANY_WDG_ICON = FEATURE_ICON;
+const static char* ANY_WDG_LABEL = "label";
+const static char* ANY_WDG_DEFAULT = "default";
+
+const static char* SOURCE_FILE = "path";
+const static char* VALIDATOR_PARAMETERS = "parameters";