violation notice verbal vs written

We have a tenant in a rental property parking his vehicle on his lawn which is in violation of the HOA restrictions. This may seem like a petty violation, however we have had a couple of complains from other members and feel it's time to deal with it. This is my first term as president and when I questioned the previous board members as to how first violation notices have been dealt with in the past, the answer was always verbal. These verbal violations have had a 95% success rate in correcting the problem mostly because property owners aren't aware that they are in violation of the restrictions. (Or so the excuse goes)

In this case as it's noted in the HOA bylaws, the property owner is responsible for their tenant(s)obligation to follow the restrictions and as the property owner is an company and not an individual(s) I feel the first warning should be directed to the company and should be written.

Any thoughts to this? Thanks for all replys.

Where exactly are they parking? The patch of grass by the street or the actual lawn?

Thsnks John and Paul. Good advice from both of you.

Kevin, the tenant parks his truck on the grass next to the driveway in front of the front door. It's a two car garage and only two cars are ever parked there... It maybe that a third is kept in the garage(?) or the offender just likes to park as close to his front door as possible.