In their practical use the Vocabulary and the Glossary fulfilled similar offices; and so they were often combined; the possessor of a Vocabulary enlarged it by the addition of a Glossary, which he or some one before him had copied out and collected from the glossed manuscripts of his bibliotheca. He extended it by copying into it vocabularies and glossaries borrowed from other scholars; he lent his own collection to be similarly copied by others. Several such collections exist formed far back in Old English times, the composite character of which, partly glossary, partly vocabulary, reveals itself upon even a cursory examination.
As these manuscript lists came to be copied and re-copied, it was seen that their usefulness would be increased by putting the words and phrases into alphabetical order, whereby a particular word could be more readily found than by looking for it in a promiscuous list of some hundreds or thousands of words. The first step was to bring together all the words having the same first letter. The copyist instead of transcribing the glossary right on as it stood, extracted first all the words beginning with A; then he went through it again picking out all the words beginning with B; then a third time for those with C, and so on with D, E, and the rest, till he had transcribed the whole, and his copy was no longer in the fortuitous disorder of the original, but in what we call first-letter order.
A still later scribe making a copy of this vocabulary, or possibly combining two or three lists already in first-letter order, carried the alphabetical arrangement
