private static byte encodeInternalStatus(boolean usingTemplate, Boolean isAligned) {
    byte flag = 0;
    if (usingTemplate) {
      flag |= 0x01;
    }
    if (isAligned == null) {
      flag |= 0x04;
    } else if (isAligned) {
      flag |= 0x02;
    }
    return flag;
  }
Including schema and pre-delete flag of a measurement, could be expanded further.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/schemaengine/schemaregion/mtree/impl/pbtree/schemafile/RecordUtils.java