SSI are special showing instructions to the fellow member Realtors of the local MLS (Multiple Listing Service) that reflect the requests of the Listing Agents clients such as: day sleeper do not call or show before 11 AM, do not let cats out of basement, dog in cage in garage and so on. SSI instructions are meant as information to the showing agent to insure a good showing experience for both the buyer and seller.
Special Showing Instructions. When Realtors show homes the homeowners are notified...in some cases homeowners have dogs, or cats, or something that they want the Realtor to know before they enter their home. Therefore the "Note: SSI"