Everything that has been said above is well and good, but in the US, we're Governed by OSHA Standard 29CFR 1910.178 and in the standard, it states:

1910.178(m)(5)(i)
When a powered industrial truck is left unattended, load engaging means shall be fully lowered, controls shall be neutralized, power shall be shut off, and brakes set. Wheels shall be blocked if the truck is parked on an incline.
1910.178(m)(5)(ii)
A powered industrial truck is unattended when the operator is 25 ft. or more away from the vehicle which remains in his view, or whenever the operator leaves the vehicle and it is not in his view.
1910.178(m)(5)(iii)
When the operator of an industrial truck is dismounted and within 25 ft. of the truck still in his view, the load engaging means shall be fully lowered, controls neutralized, and the brakes set to prevent movement.


What this means is by law, when the lift is parked, the mast is lowered and tilted forward for the forks to be flat on the ground. So as a company, if you do not follow this action, you can be held liable in case of an accident. Why open yourself to this liability?