A most commendable feature of modern cataloguing is the explanatory notes and other annotations appended to catalogue entries. These are for the most part to be found in the lists of additions to libraries published monthly, quarterly, or annually; such publications lending themselves readily to this descriptive form of cataloguing. The classified catalogue has also the advantage over the dictionary form for this purpose, because, rarely having more than a single entry for each book, the question as to where the note is to go does not arise. The dictionary catalogue having two or more entries, the addition of annotations enlarges it materially, besides presenting the difficulty of deciding to which of the entries the note is to be attached, if not to all. Some notes are better under the author-entry, and others are more appropriate to the subject. Nevertheless, some fully annotated dictionary catalogues have been issued, notably Mr. C. W. F. Goss's catalogues of the Bishopsgate Institute Library and Mr. W. E. Doubleday's Hampstead Public Library catalogues.
When annotations are given, they should be pithy, to the point, and, as far as possible, free from criticism. A bookseller may have some strong religious leanings or political opinions which he can afford to publish by means of notes in his catalogues without anybody being more than amused thereby, but the wise public official, as the servant of all creeds and parties, will respect all alike, and take care, if only for his own sake, that he does not hurt the susceptibilities of any. He will keep his personal opinions to himself in a "water-tight" compartment, where they cannot affect or influence his public work, whether it be in cataloguing or in book-selection. It is greatly to the credit of public librarians that they pursue this policy as a mere matter of course, their training enabling them to view all literature broadly, without prejudice or any reference to the bias of the contents of books. To say this, does not mean that a cataloguer may not attach a note to a controversial book of any kind indicating the point of view taken by the author, but he should do so without expressing his own opinion.
Some annotations are nothing more than a repetition or paraphrase of the title-page, and so add nothing to the information contained in the catalogue entry. They appear to be given upon the supposition that every book in an annotated catalogue must have an annotation, but this is a mistake, as the majority of title-pages admirably summarize the contents of books, for which purpose they exist. It is when they fail to do this, or do it indefinitely, or when the book has some especial feature not noticed in the title to which it is worth while directing attention, that the annotation is required and proves of value.