- * "format" struct. Returns the numeric version. On error, -1 is returned,
- * format->version is set to -1, and all other fields in the struct are
- * undefined.
+ * "format" struct. Returns the numeric version. On error, or if no version is
+ * found in the configuration, -1 is returned, format->version is set to -1,
+ * and all other fields in the struct are set to the default configuration
+ * (REPOSITORY_FORMAT_INIT). Always initialize the struct using
+ * REPOSITORY_FORMAT_INIT before calling this function.