The Major-word-key Service builds a Word-key based on the major word of a multi-word name. It is similar to the Word-key Service except that it accepts a full name consisting of multiple words. One word (the Major) is extracted and processed by theWord-key Service to produce a similar 3 byte Wordkey.

This Service is used when a short (and rough) key is needed based only on the major part of a name, to be used on its own or in conjunction with other keys. By its own, on a large file, the 3-byte Word-key is not selective enough for efficient retrieval. NAMESET should normally be the Service that is used to build keys on names.