How does a Transaction NO generated when the Last No is not defined in the Transaction Source?

Hi All,

Normally, to generate an Automatic Numbering for a AR Transaction, we will define it in the Transaction Source.

What when we do not mention any Last Transaction Number and enable the "Automatic Transaction Numbering" check box, and do not enable "copy document number to the Transaction Number" option, on what basis the Transaction Numbering gets generated?

Also it is noticed that the Automatic Number that was generated is not in sequence. It is skipping values in between. Can anyone please help me to understand on what basis this random numbering is getting generated?

Thanks in advance.

Regards,

Naresh Kumar.