How to protect a buffer from being deleted by accident?

[Adalbert Perbandt]

Hi there,

At my site we're using clearcase mode (clearcase.el) for a long time
with very few problems. Some time ago one of our users deleted the
buffer "*clearcase*" inadvertently.

Now I'd like to provide a simple mechanism which disallows for
deletion of this buffer. I think, it would not be too complex to
implement this but I don't know any simple method to get it
done. Maybe there is a posibility to mark a specific buffer as
"undeletable" or so.

Any hints are welcome.

Regards,

Adalbert Perbandt.