La “Collation Sechehaye” du Cours de Linguistique Générale de Ferdinand de Saussure / édition, introduction et notes par Estanislao Sofia. (OCLC #954052946)

This title appears to be criticism/interpretation of a famous work, Course in General Linguistics by Ferdinand de Saussure. The copy we found for the book in hand had this LC call number assigned:

    P121.S369 S64 2015

It seemed odd that it had two cutters (one for Saussure, another for the editor?) so I checked the LC schedule. P121 is “Philology. Linguistics—Language. Linguistic theory. Comparative grammar—Science of language (Linguistics)—General works”, so it makes sense that our copies of Saussure’s work itself have call numbers like:


But what about that second cutter? Is there a rule somewhere in the Shelflisting manual about adding 9 and then a second cutter for the editor? I checked our catalog, and found two other titles around P121.S36 in our catalog with that same construction, but don’t know where it comes from.

G340 in the shelflisting manual says that for criticism/commentary of a work classified with one cutter, you should start with the call number of the main work, add the digit “3” and then a second cutter based on the main entry of the criticism/commentary work.

So is this a typo? (Repeated by several catalogers for commentaries of the same work?) Or is there a rule I haven’t yet found?