What's the deal with bill of sale? no title

[Thang Cao]

So what's the deal with a home available for sale without a title? Situation is park owner wants to sell a home without a title.  Current resident just up and left about two weeks ago. Park owner said they can sell with a bill of sale.  And I want to buy.

Spoke to a local investor and he said this is common.  My question is why? Is it simply because the owner just don't want to pay tax on it?  How normal or often does this occur?

Thanks in advance.