A Colophon is an editorial summation of what was just written. It is found throughout the Old Testament. Here is an example at the end of Ecclesiastes:

9 And moreover, because the preacher was wise, he still taught the people knowledge; yea, he gave good heed, and sought out, and set in order many proverbs.
10 The preacher sought to find out acceptable words: and that which was written was upright, even words of truth. (Ecclesiastes 12)

The Book of Mormon also contains Colophons. Here is an example in Nephi:

1 And all these things did my father see, and hear, and speak, as he dwelt in a tent, in the valley of Lemuel, and also a great many more things, which cannot be written upon these plates. (1 Nephi 9)

Within a Colophon there often appears the phrase “thus ended” or “thus endeth” or just “ended” throughout The Book of Mormon. This was discovered to be a standard literary form for concluding a colophon in Mesopotamian documents. (H. Hunger, Babylonische und assyrische Kolophone, Neukirchen: Butzon and Bercker Kevelaer, 1968, 15.1, 19.1, 43.4, 109, 1.)