Jenn,

> 1) What type of data are you currently putting in the top-level <extension> element?

We use the <extension> element for local holdings info and for non-roman
data. If a MARC record contains 880 fields, then we create a second
<mods> element using the 880s and stick it in <extension>. You can
see an example here:

    http://copac.ac.uk/search?ti=Qian+gu+zhi+mi&rn=1&format=XML+-+MODS

> 2) Do you have specific cases in which it would be helpful to you to have <extension> inside a specific MODS element rather than at the top level to convey additional semantics?

No.

> 3) Have you made changes to the MODS schema locally to allow for additional elements not in the MODS schema?

No.

Regards,

Ashley.
-- 
Ashley Sanders               [log in to unmask]
Copac http://copac.ac.uk A Mimas service funded by JISC