- * one of the comma-separated items given. If not, an error is
- * reported; otherwise the index of the matched item is
- * returned.
+ * one of the comma-separated items given. The return value is
+ * the index (zero-based) of the matched string in the list.
+ *
+ * The flags control the behaviour if no exact match is found.
+ * If @ENUM_ABBREV@ is set, and the current token is a left
+ * substring of exactly one of the possibilities, then that one
+ * is chosen. If @ENUM_NONE@ is set, the value @-1@ is
+ * returned; otherwise an error is reported and the program is
+ * terminated.