The library volunteers who make the calls get asked this question often. Libraries are bound by NY State law to protect the privacy of  library records. When our volunteers make phone calls to alert people that a reserve book has come in, they are only given the name and phone number of the person to be called and are not given the titles of the item being held. If you need to know the title that is being held you can call the library and give them your library barcode number and the staff member you speak to can look up the title for you.  Even more convenient perhaps is to sign up for email notification where you will get an email that includes the title of the item on hold for you.