The type of values you enter in this tab depend on the use context of the Segment. The tab contains fields which are specific to '00' or other Segment you have defined.
Depending on the segment type, the information required in the definition are different. For a non-'00' segment, you indicate the action code value and presence check options. For a '00' segment, you enter a value in the action code field which is quite different and you need to indicate the data element code which identifies the transaction type.