To set the record right:
P-plate is mandatory in the first year in other to warn others that you are still a new and inexperienced driver. Therefore, if you never put it on during this time, you will get caught and licence revoked.
After first year, you can take down the P-plate, as it is assumed you have acquired a year of driving experience. However, some drivers who are still unsure about their driving can and should put up the P-plate, as this is to warn others to be cautious of you. Not a crime if you put it up after the first year is over.
Finally, P-plate dun mean lousy driver and non P-plate dun mean good driver. Cheers!
