| bhid | household identification number |
| bpno | person number |
| blacbm | month of birth – adopted child |
| blacby | year of birth – adopted child |
| blacsx | sex of adopted child |
| blacst | status of adopted child |
| blacyb | year adopted child joined resp. hh |
| blaclv | adopted child still lives in resp. hh |
| blacyd | year adopted child died |
| blacal | age adopted child left resp. hh |
| blacno | adopted child number |
| blacby4 | year of birth – adopted child: 4 digit |
| blacyb4 | year adopted child joined hh: 4 digit |
| blacyd4 | year adopted child died: 4 digit |
| pid | cross-wave person identifier |
| pidp | Cross-wave person identifier (UKHLS) |