Definition
BIRTHTOHHVIS2YR indicates whether any visitor to this household gave birth during the past 2 years ("in this city/town/village or outside"). By definition, household "visitor" is a temporary status, so this question presumably encompasses visitors not currently present in the household.
The related variable BIRTHTOHHVIS2YRNO reports the number of births to visitors to this household during the past 2 years.
The information in BIRTHTOHHVIS2YR is taken from the household record and, as a characteristic of the household, applies to usual household residents, not the current temporary visitors. Researchers may wish to exclude current visitors using the RESIDENT variable (with visitors coded "2") when women, children, or births are the unit of analysis, and using the HHRESIDENT variable when household members are the unit of analysis.