Standardization problems

Standardization is definitely a complicated process: tons of MIGs are available on the web but end users always find the way to create unpredictable variables to prevent a correct data processing.  

Recently, I'm struggling with an issue about the VAT number of freight forwarders/custom brokers reported into COREOR D00B: apparently, it's unclear if the nation code has to be included, as NAD02, in NAD segment when reporting the VAT number. 

In terms of message structure, that's the issue: 

NAD+FW+IT03450730100:160:ZZZ'

OR

NAD+FW+03450730100:160:ZZZ'

Value reported in NAD02, is the target value to transcoding hence the prefix 'IT' makes a big difference when applying the mapping rules and the translation rules.

I'm quite interested in collecting feed-back about this topic: in case you are experiencing the same issue in your EDI environment, you can drop a comment here!