Not sure which is the best section for this, so hope nobody minds me shoving it under 'other'.
If you were (are) divorced, you've brushed ex-H's name under the carpet but ex-H's brother sends your child parcels/cards with his surname - still the proper legal name - on them, would it get your back up? Would you ask them not to?
My brother and his wife have been divorced over 10 years - they have a teenage daughter, my niece, who lives with her mum. Bit of an acrimonious split - ex-SIL was something of a manipulative witch, and has said all kinds of hurtful and untrue things about my brother. But niece has a great rapport with me and DW, and we are still very much in touch despite her mother. So are her grandparents (my mum and dad).
Niece was born with the family name, i.e. my brother's, ours. (His wife took his name.) When niece was about 8 she started telling everyone she 'had two surnames'. And somewhere along the line our family name has been quietly dropped. But that is still my niece's name on her passport and will be on her driving licence if she learns. I don't think it can be legally altered without both parents' permission (?) and there is no way in hell my brother would agree to that. Ex-SIL seems to have got her to drop our family name purely out of spite.
Most of the time we email, so it's not an issue, but I still use our family name when writing to her for birthdays, Xmas etc., and so do my parents. Why? Well, why not? It hasn't been changed officially, and I haven't been officially informed of any change. (Evil ex-SIL has no contact with us, you may have gathered.) Niece herself stays diplomatic by using her first name & initial - because as it happens, both surnames start with the same letter.
What's the verdict of the Mumsnet Jury?
(NB: my brother is not the kind of dad who has to be chased for money all the time and is never there - quite the opposite. As far as I know, the divorce was a result of "irreconcilable differences" rather than anyone doing anything "wrong".)