Mr. Cutter follows this, and adds to it (rule 25):—
"In Danish names, if the type å is not to be had, use its older equivalent aa; in a manuscript catalogue the modern orthography ä should be employed. Whatever is chosen should be uniformly used, however the names may appear in the books. The diphthong æ should not be written ae, nor should ö be written oe; ö, not oe, should be used for ø.
"In Hungarian names write ö, ü, with the diæresis (not oe, ue), and arrange like the English o, u.
"The Swedish names, ä, å, ö, should be so written (not ae, oe), and arranged as the English a, o."
The Cambridge rule (10) is as follows: "German and Scandinavian names, in which the forms ä, ö, ü, å, occur, to be treated, for the purpose of alphabetical sequence, as if spelt with ae, oe, and ao respectively. In German names ä, ö, ü, to be printed ae, oe, ue."
The Library Association rule (44) is: "The German ä, ö, ü, are to be arranged as if written out in full ae, oe, ue."
The first part of the Cambridge rule and the whole of that of the Library Association is likely to lead to confusion. The only safe way to deal with these letters is either to spell them out, or to arrange them as if they were English letters. The English alphabet must be pre-eminent in an English catalogue.
The rule that M', Mc, St., etc., should be arranged as if spelt Mac, Saint, etc., stands on a different basis from the above, and the reason is, as stated by Mr. Cutter (rule 173), "because they are so pronounced." When we see St., we at once say Saint, and therefore look under Sa.
The Index Society rule enters fully into this point, and explains what is a difficulty to some: "6. Proper names with the prefix St., as St. Albans, St. John, to be arranged in the alphabet as if written in full, Saint. When the word Saint represents a ceremonial title, as in the case of St. Alban, St. Giles, and St. Augustine, these names to be arranged under the letters A and G respectively; but the places St. Albans, St. Giles, and St. Augustine will be found under the prefix Saint. The prefixes M' and Mc to be arranged as if written in full, Mac."
When several titles follow one heading, it is necessary to use a dash in place of repeating the heading, and there are one or two points worthy of attention in respect to this dash.