how to delete invoiced purchase order.

I selected the data safety level to none, But still I am not getting an option to delete the invoiced purchase order, And also tried under periodic >> clean up but did not work,. so is it a design made not to delete the invoiced purchase order ? or is there any other functionality to delete the purchase order.

Do you mean the red delete option in the header of the purchase order is greyed out? That would be security, or possibly an ISV input. As standard with the correct security rights you can delete it by pressing the delete icon.

[mention:713992e2cc394574827989c4d4af9bbb:e9ed411860ed4f2ba0265705b8793d05] thank you for the clarification , And also I need a help how to delete the intercompany sales order and purchase order. Suppose if I use sales and marketing >> periodic >>clean up>> delete sales order and suppose if my sales order is a intercompany order then can I delete this sales order and its related purchase order .