You can print out the official rule as a prove for the POE officer.
Tony,
Why do you think different POE or PFI will act differently according to the rule changes?
In what particular situation/ classification it needs to be justified for a 3 yr or 2 yr or 1 yr petition?
Wouldn't the length of years stated your petition letter(for employer) be sufficient to justify?
Your comment implies that if your letter requested 3 yrs, but given a specific classification POE will issue could issue partial length. What justification are they following?
I thought it is either a NO or Go.
If your job / education does not fit, they won't even issue you a TN.
If your job, letter, education synced up with the regulation, they will issue you a
TN according to the requested peroid. I can't think of a reason why would they give you partial length of the requested.