Hi 
I think the we got close enough with;
"ODF 1.2 Extended (compat) is written to be more compatible with legacy software that still uses ODF 1.0 and 1.1, as well as with current
software that uses pure ODF 1.2 (ie 1.2 without the Extended
features)."
I was expecting people to change it around a bit but it seemed to be
close enough. There had been a paragraph about specific examples of
"legacy" and "current" software but it probably is better to avoid being so specific.
<quote>
So if you're only using current versions of LibreOffice, you don't
need that compatibility format. But when you exchange/process
documents with non-LibreOffice (and non-OpenOffice, or just
ancient versions) software that doesn't understand ODF 1.2 format,
then this format will (probably) help.
</quote>
On the other hand the quote above helps us understand exactly what is being talked about and it's very easy for non-geeks to understand so maybe that
should be re-worked instead? Perhaps to;
"If you're only using current versions of LibreOffice, you don't need the "ODF 1.2 Extended (compat)" format. But if you exchange/process documents with non-LibreOffice (and non-OpenOffice, or just ancient versions) software that doesn't understand ODF 1.2 format, then this format will (probably) help. So, if you ever use ODF 1.0 or 1.1 or 1.2 (without the Extended features) then this compatibility format can be used instead."
Regards from
Tom 