If a legal concept changes slightly, a new term may be introduced to replace the old.

For instance:
enduring power of attorney (EPA) up till September 2007
lasting power of attorney (LPA) from October 2007

These are the common powers of attorney you might take out for an aged parent while they are still compos mentis and have registered later. There are definite differences so the distinction is necessary.

But what about family-law terms like
custody > residence
access > contact

See John Bolch, A matter of terminology:

Perhaps the best known example – one that still catches out lay people (and some older lawyers) – is the new names given to the two main types of children’s order by the Children Act 1989. Out went the old terms ‘custody’ (which, incidentally, is still understood throughout the English-speaking world) and ‘access’. In their place came ‘residence’ and ‘contact’. I acknowledge that ‘residence’ has a different meaning to ‘custody’, but is a ‘contact order’ really that different to what an ‘access order’ used to be?

See that article for more on: child arrangement, ancillary relief > financial remedy, Divorce Registry > Principal Registry, registrar > district judge, child mnaintenance > child support > child maintenance, absent parent/person with care > non-resident parent/parent with care > paying parent/ receiving parent > parent who pays/parent who receives

As John writes about custody and access, these are terms familiar throughout the English-speaking world. It’s all quite a pain for translators out of English, and also into English, especially if they don’t translate from German for one specific jurisdiction.

In a later post, also on Marilyn Stowe’s family law blog, (Are the terms ‘custody’ and ‘access’ really degrading?). John Bolch writes that the terms custody and access are still sometimes used but some regard them as degrading. This sounds as if the change in terminology was regarded as a move towards PC.

My personal bugbear is the replacement in England of plaintiff by claimant. There was no change of meaning that might have justified this: it was purely done because the hoi polloi were not expected to understand it. But the term remains used in Ireland and hence in the EU, in the USA, Canada, Australia, New Zealand and elsewhere. When I translate into English for German clients my translations are not just for England so I always write plaintiff.