Revenue allocation using combined/Nested IF statements

Hi,

I have been asked to go through some information which has over 200 000 lines, what I need to do is as follows:

where order number is unique, revenue source = "Unique"
where order number appears more than once, check division to see if it appears in more than one division, if it does revenue source = "Cross Selling", if it does not then revenue source = "Divisional Package"

I need all of the above in formula line which will be inserted in the revenue source column

I have attached the file with a sample of the information I am using.

Thanks in advance,