Maintain Number Ranges for different document types

Normally when you create a sales order / delivery etc , you can see that the document numbers generated are not random but sequential and according to certain rules. (Ex: Its hard to see a document number 00000000001. These number ranges are not same for all types of documents.

SNRO : Maintain Number Ranges for different document types
SNRO : Maintain Number Ranges for different document types
One can maintain the number ranges using TCODE SNRO . In this transaction you can set or edit the number ranges for certain types of documents.