Total number of persons living in the household

In the CPS July 2015 Computer and Internet Use File, HRNUMHOU asks for the “total number of persons living in the household” with 0 as the minimum valid entry and 16 as the maximum value. If this question is coded as 0 does this mean the respondent lives alone, does this mean the house is vacant, or does this mean something else entirely? Thank you!

According to the Technical Documentation, it looks like records with HRNUMHOU==0 are households that are vacant. Note that the variable HRNUMHOU is an original CPS variable and not an IPUMS integrated variable. In IPUMS CPS the variable NUMPREC summarizes the same information. Also, when extracting the (default) rectangular data structure, all vacant households are dropped in IPUMS CPS. Therefore, the minimum value of NUMPREC is 1, indicating a single person household.