How "C1-All Vac Res Lts&Vac Res Tr<5 Ac" =Only $250 Tax per lot?!

[Glen Thomas Corder]

Is this a little gold nugget of information and/or can anyone elaborate so that we can understand this set up. 

I met someone recently (older gent) that owns over 100 lots at 7,000 Sq. ft / 0.160698 acres in Montgomery County Texas, and when looking I seen that all of the lots he has are showing the C1-All Vac Res Lts&Vac Res Tr<5 Ac as the "State Code" and the Total Assessed/Taxable Value is $250 ?!! Therefor the property tax is ONLY $7.45 per lot (annually). *He has had them for years and they're all rented out...