No

While you can... don't.

Those field values show up in more tables than just those. For example, we needed to do a renumbering process and to change the order number field we had 11 tables to update. And for Invoice numbers we updated 17-18 tables.

For one of my clients who has Extender, we've added business logic that says you can only enter an existing document number or *** NEW ***.  No more documents with weird characters.

if a user accidently overrides the *** NEW ***, it will NOT work if they just type that in again.  we had a few people try to be smart and then we had an order with it. 

I'd be interested in how you used extender to stop the change.  That's a good idea.  

I chopped out a bunch of other logic so there might be a bug or two in this but this is a screen script that will only allow the user to enter *** NEW *** or an existing invoice number - otherwise an error message is thrown back at the user.

# OE1900

from accpac import *

vInvoiceHeader = None

def main(args):
    MyUI()

class MyUI(UI):
    def __init__(self):
        UI.__init__(self)
        self.createScreen()

    def createScreen(self):
        global vInvoiceHeader

        vInvoiceHeader = openView("OE0420")

        self.dsH = self.openDataSource("dsOEINVH")
        self.dsH.onBefore = self.dsH_onBefore

        self.show()


    def dsH_onBefore(self, eventname, field, value):
        if eventname == "PUT":
            if field == "INVNUMBER":
                if self.isValidInvoiceValue(value) == True:
                    return Continue
                else:
                    error("Invoice not found.")
                    return False

    def isValidInvoiceValue(self, docNumber):
        if docNumber == "*** NEW ***":
            return True

        vInvoiceHeader.order(6)
        vInvoiceHeader.put("INVNUMBER", docNumber)
        if vInvoiceHeader.read() == 0:
            return True
        else:
            return False

interesting, thanks for sharing.  We have extender as part of a package but never really messed with stuff like this because we weren't sure if it was going to be a system drag at all across 100+ users.  I'm going to dig into because users are constantly overriding the NEW field.

For sales orders you can hide the order number field

this is very clever. but then users could not retrieve orders to edit before shipment