I looked up acronyms for PU, the only one I could find relating to smell would be pig urine. But all of the other info about it I found said that it doesn't actually stand for specific words starting with the letters P and U. Here is the best answer I found from the website- The Phrase Finder:
National Transport Authority > Taxi and Bus Licensing > Taxi > SPSV Driver Licensing > Renew an SPSV Driver Licence. A regular SPSV driver licence is valid for five years and is renewable; a local area hackney driver licence is valid for three years and cannot be renewed. (The holder of a local area hackney driver licence who wishes to continue operating can, however, apply for a new licence.) To renew your SPSV driver licence, you must hold: 1  A valid full Irish driving licence or equivalent; 2  A valid SPSV driver licence; 3  Must be Tax Cleared with Revenue.
The renewal period for driver's licenses varies by state. It can range from three months to as much as a year before the expiration date, and up to two years after the expiration date.There are usually no restrictions on renewing early unless you are under the age of 21.he renewal period for driver's licenses varies by state. It can range from three months to as much as a year before the expiration date, and up to two years after the expiration date.