字段帮助 (GDE) 

A structure is used to define the entry framework for an accounting journal. It is possible to select the entry screens, the account structure to be applied and to define a default value and a specific control for each field. The structure is identified by an alphanumeric code of 1 to 5 characters used to select the structure in journal entry mode.

The STD code transaction is used to view and/or modify the accounting journals as a whole, whatever the original transaction.
In the same way, the STDL and STDA code transactions are used respectively to view and/or modify the batches and the analytical journals, whatever the original transactions.