In Britain, the 'freeman' status entitled a man to a range of privileges that have changed over time.
They included the right to vote, the right to drive cattle and sheep over city bridges, the right to be hanged by a silk rope if sentenced to execution, and the right, if apprehended drunk by police, to be sent home rather than to a cell.
While these privileges are now merely quirks of history, it remains an interesting question which, if any, the swashbuckling batsman would most like to avail himself of.
McCullum is already free to vote in national elections and, if turnout rates in local-body polls are anything to go by, chances are he'd have little interest in deciding the future of Wellington's grass berms and sewers.
New Zealand's judges are not at liberty to condemn wrongdoers to death nowadays, so the silk rope is redundant.
And as for the blind eye from the constabulary, it's about as easy to imagine McCullum stumbling down Courtenay Place in the wee hours as it is Daniel Vettori turning one square.
That leaves the livestock rights. McCullum is no farmer, but his predilection for horse-racing has been well documented.
So instead of driving sheep through the Mt Victoria tunnel, he might want to persuade Wade-Brown to enlarge the concession to his fillies and geldings.