A snintercom is an advanced wireless intercom, that also has DTC (Document Transfer Capacity).
Its base portal is in Mrs. Rosebank’s office. So if she wants to make verbal announcements to the whole school she can do so. But the big advantage is if she wants to send everyone a paper memo or a pile of documents or even a book, she can use the snintercom. Likewise they can send documents to her. The maximum capacity for a single send is 7 books.
Collum Ollum, for fun, once tried to send the Complete & Comprehensive Encyclopaedia of Grobsnots (21 volumes) and he jammed the system. It took technicians a week to repair and the encyclopaedia was lost forever. He got into a lot of trouble for it.