This is Useful Feature for user to Set Order ID as User define and requiremenet.

Set Sales Order Number
If user has to start Order Id number start from particular number while placing Order then user has to set that number as per below:

Select Set Sales Order Number >> Enter Required Number in Diolog box>>Click on OK.

Sales Order number entered by user will be auto increament as per order placed.

Add Sales Order Series

If User has to add prefix on order Id and before order Id Number then User has to Set that particular Prefix as below:

Select Add Sales Order Series >> Enter Required Prefix in Diolog box>> Active/Enable it >>Click on OK

Whatever is the active prefix series and number from setting, that will be display in all Sales Order Forms.

Note: Only Sales order number will be auto-increament but order series will be as it is constant till user change it.