[Koha] Introduction / Hiding specific item types

[Mirko]

Hello everybody,

I've been reading this list for 9 months now and learned a lot here.
I'm in the process of managing the migration to Koha for a media
centre/ library at a university in Berlin/ Germany. The facility's
specific purpose is to provide material (print, audio, video,
software) for learners of foreign languages.

I have several problems to solve and I hope you can help me a
little. It may be useful to say that I'm more of a tech-person in
this context, not a librarian. The first problem I would like to
address is the following:

Among other things we have an inventory of old TV recordings. We are
obliged by our legal department to not show OPAC entries of these to
the general public -- meaning our (old) OPAC is restricted to the
university network, making us invisible to everybody outside of that
network.

It would be great to find a way around this with Koha. Is it
possible to show some specific items in the OPAC only
a) to people of specific patron groups or
b) to people of a specific IP range
while invisible to others (and while all other items are visible to
everyone)?

I've read about shadowing, but I understand it hides items from the
OPAC completely, showing them only in the staff client. That is not
what we need, people coming to our facility are supposed to find
everything in the OPAC. Is there some other way, like hiding a
complete category of items?

Thank you for reading all this,

Mirko