SAP Message WM450 - Please note: assortment number & has already been used for a customer

Diagnosis
You wish to create a new assortment. The assortment number has,however, already been used as a customer number.

Procedure
Release 4.0 : The function cannot be carried out.
Release > 4.0 :
You can ignore this message and the assortment will then be createdwith this number. Please note, however, that this may lead toinconsistencies in the analysis of cascading assortment assignments.