When you display or change line items, they are displayed in the standard sort sequence. The standard sort sequence is determined internally by the system. To do this, the system uses the following document fields:

• Clearing date
• Clearing document number
• Assignment
• Fiscal year
• Document number

The line items are then sorted as follows:

• Cleared line items are always sorted by Clearing date, Clearing document number, and the remaining fields. Clearing transactions can therefore be considered together.
• Open items are always sorted by the Assignment field and the remaining fields, since the Clearing date and Clearing document number fields are not filled for open items.

From the standard sort sequence, you can switch to another sort sequence. The system offers you fields to sort from, from which you can select the fields you require. If you require additional fields, you can add these to the selection.

You have the following options for changing the sort sequence:

You can flag account line items that are to be processed together. To do this, enter the same indicator in the field Assignment for each line item in the group.

The contents of the Assignment field are used:

• To sort items when you display, clear, and change them
• As a selection criterion
• When clearing payments using the functions "posting with clearing" and "incoming or outgoing payment"
• For maintaining accounts with the Account clearing function
• For displaying and changing line items
• Subdividing one-time accounts and head-office accounts

You can define the contents of the Assignment field as you wish. You have the following options:

• The system can enter the contents automatically. To do this, in the account master record, enter a key that represents the layout rule you want to use for making entries in the Assignment field. This allows you to set up account-specific sort sequences for line item display.
• You can enter the contents of the field yourself when entering a document.

The layout rule determines which entry from the document header or line item should be entered in the Assignment field at the time of posting. You define the keys and their layout rules in Customizing. The standard system is delivered with pre-defined layout rules. SAP recommends that you use these rules.

You can change the layout rule key in the master record at any time. The new layout rule takes effect from the time the change is made: That is, all line items posted afterwards are displayed according to the new layout rule. The assignment remains unchanged, however, for the documents already posted.

To define your own layout rules for the Assignment field, you specify a key and up to four fields for each rule. The contents of these fields are then copied to the Assignment field in the order you define. You can use any document header or line item field in your layout rule.

You can also have the system copy just a part of the contents of a particular field to the Assignment field. To do this, you have to specify the number of characters copied and the position from which they are copied.