"Adoption" 1919

I know that there were no formal adoptions then, but if a baby from a children's home was taken in by an unrelated couple ( well, only related in that one of the new "parents'" brothers was a local poor law official), would there be any formal documentation of any sort?

As I write this, I have just realised that if there are any records, I guess they would be closed

Sorry if I've asked this before - I can't remember whether I have or not!