Field help (CODNUM3) 

The counter code associated to the defined type of order must be entered, whether the number allocation is automatic or manual.
It is therefore recommended to have previously defined a sequence number counter in the Sequence Numbers table (that can be accessed by tunnel from this field).

When the counter is used for the Portuguese legislation, the sequential number is applied to the document when it is subject to the electronic signature and SAFT-PT (Standard Audit File - Tax) payment processes. The parameter entitled PORDKS-Electronic signature Portugal(LOC chapter, POR group) must be set to: Yes, and the DKS-Electronic signature must be active.
The counter must have the following structure:

Between the first and the penultimate component, the complement can be used as an option. Although, the complement is mandatory for purchase auto-invoices. If the structure is not properly defined, a blocking error will occur once the document is validated or signed.