The title of the above book is misleading. This book is not just an index to passenger lists; it is an index to all records that allude to immigrant status. These can include census records, land records, naturalization records, and many others. You will find the name of the immigrant, a date at which he appeared in the records, the place where the record was found, and the book or article from which the index was taken. Note that the date is not necessarily the date that your ancestor immigrated. It is a date when your ancestor was in that place. The series originally contained three volumes, and it has annual supplements. The title changes with each volume as the number of indexed passengers increases. You must check every volume of Filby’s indexes if you use them in print.