commercial use could mean abuse.

if it had multiple drivers, etc, it may have been a truck that was pounded on.

get whatever contact info you can on anything it says service-wise (my truck was serviced at the dealer and was inspected at a gas station and serviced there as well prior to me owning it and it came up as such on the carfax) and make as many calls as you can.

the more you know the better

but nothing speaks better than driving and inspecting it yourself.