Yes David, "in law' was a term used for step-relatives, half-relatives and relatives by marriage and 'adopted' ( though there was no formal adoption before 1927) It seems it covered anyone who was considered a relative by law or custom - so covered a lot more than we understand by the term today. The illegitimate children would have been informally adopted often by their mother's new spouse. HTH Anne On 28 Dec 2008, at 11:37, david chambers wrote: > Good morning all, > I am finding on a lot of census return's illegitimate children are > down as 'in law' > is this a common practice? > many thanks > David