<Tr> <Th_colspan="2"> foot </Th> </Tr> <Tr> <Th> Unit system </Th> <Td> imperial / US units </Td> </Tr> <Tr> <Th> Unit of </Th> <Td> length </Td> </Tr> <Tr> <Th> Symbol </Th> <Td> ft </Td> </Tr>

What is the abbreviation for feet and inches