18 And it came to pass that in the ending of the thirty and fourth year, behold, I will show unto you that the people of Nephi who were spared, and also those who had been called Lamanites, who had been spared,
The phrase in italics caught my attention. What an unusual way to refer to a group of people! I set out to figure out what Mormon is referring to. I found the answer in 3 Nephi 2:
14 And it came to pass that those Lamanites who had united with the Nephites were numbered among the Nephites;
15 And their curse was taken from them, and their skin became white like unto the Nephites;
16 And their young men and their daughters became exceedingly fair, and they were numbered among the Nephites, and were called Nephites.
This is perhaps the most subtle example of internal consistency I've found so far. So subtle, in fact, that I felt the need to look up both passages in the printer's manuscript to confirm this isn't an artifact of later versions. (It isn't, see pages 365 and 379 of this link if you want to see for yourself.)