What are Transaction References?
Each type of transaction, for example, a check payment, sales order, movement order needs a unique reference number, which must be set up before the transaction can be processed. You can define the layout and content of transaction references depending on your requirements. For example, if you store  a check number as a transaction reference you may need part of the reference number to include the Operator Id, date or a specific number.
Once you have created a transaction reference, you can include it in the document format where it is to be used, so that the document uses the correct formats. For example, the document format for a sales order may include the transaction reference for the sales order. Default references are held in the Purchase Business Setup, Sales Business Setup and Inventory Business Setup. The defaults are used if there are none defined on the document format.
Transaction references can contain up to four parts which are each defined separately. It is not mandatory that all four parts are used.
You can use analysis to change the contents of any or all parts, depending on the characteristics of a transaction. See What are Analysis Dimensions and Codes? for more information. For example, a different prefix for each warehouse. If you use a code which exists on an order line, the code on the first line processed is used.
You can use transaction references in conjunction with number streams, which are used to define the next available number in a transaction reference sequence.

The Transaction References Setup (TRS) form contains the following fields:

Transaction Reference Format
An identifying code for this format.
Header information also contains Description, Status and Lookup Code fields.
Transaction Reference Sections
The format of a transaction reference can be broken down into four parts, each of which has a separate section on the form so they can be defined individually. It is not mandatory that all four parts are used. Each of these sections contains the following fields:
Type
This defines the type of data of the part. The corresponding values are defined in the Value field. The options are:

Use Analysis
Check this box if this part of the transaction reference is to be varied by referring to analysis held on the transaction.
Value
The value for the part, depending on the type of data defined in the Type field. That is:

Number Stream - enter a valid Number Stream. Constant Value - enter the value. Operator Id - leave blank. Date - see the How to set up a Date in a Transaction Reference section below User Input - leave blank.

Length
The number of characters for the length of the part.
Delimiter
The character to be used between this part and the next part of the transaction reference. This field is optional.
Note: If this field is left blank, the default value of space is inserted when this Transaction Reference Setup is used. You must set the delimiter to '0' zero for no delimiter to be inserted.