What features of LO are non-ODFv1.2?

Hi

As we all know, LibreOffice default file format is ODFv1.2 Extended, which is 
correct ODFv1.2 with some non-standard extensions.

If we are talking about document interoperability, we can reasonably assume 
that other applications try to comply with ODFv1.2, as published by OASIS. 
They may not display documents written in LO exactly the same as LO does, 
because they are free to ignore properties that makes "Extended" part.

My question is:
is there any kind of documentation or other resources that points out which LO 
capabilities are non-standard? If so, where can I find it?
Or do I have to go through LO release notes and for each new feature check if 
it exists in ODFv1.2 specification?

It would be very useful for me (and perhaps other users), because I would like 
to know which functions that I use are not interchangeable with other ODF-
compliant applications.

Thanks in advance
-- 
Best regards
Mirosław Zalewski