Thank you to everyone for your thoughtful replies (and to IMBER for confirming my suspicions... perhaps a change of meds would help
?).
While I am quite well-informed about copyright infringement in general, I find the subject very murky when it comes to publishing a book of ones family history with images pertaining to things like BMD transcriptions (not reproduction of original certificates), census records, extracts from tithe applotment books, etc.
Perhaps the clearest statement from a government agency I have found on this side of the pond comes from a Q&A in the publication "Reproduction of birth, death and marriage certificates" by the the National Archives (
https://goo.gl/61h6J8).
Q. I want to publish some certificates in a book I’m writing. Can I do this and do I need to get anyone’s permission before I publish?
A: The layout of all certificates are protected by Crown Copyright, so if you are publishing these in a book or online publication you should acknowledge Crown Copyright (you don’t need to do this if you’re just placing them on Facebook or similar). You do not need to approach GRO or The National Archives for permission. But do bear in mind that if any of the certificates relate to living individuals you need to consider the Data Protection Act provisions above and make sure you have their permission to publish.
No mention of "commerical use". Does the same apply for other types of government records commonly used in family history (estate records, census returns, applotment books, Griffiths Valuation)? Does the Republic of Ireland have a different policy?
Using the links kindly provided by Sinann, I will write the government agencies directly and see what they have to say.
Thanks once again.