This list of taxable items was difficult to copy. Oliver Cowdery’s first error was to write an ampersand after “one fifth part of all they possessed”, but then he erased the ampersand, undoubtedly because the original manuscript had no and here. This lack of and results from the fact that the phrase “a fifth part of their gold” is the first item in a following list. Earlier, in LDS editions from 1849 through 1911, there was a colon after the initial “one fifth part of all they possessed”. The use of a colon clearly shows that the following text contains a list of items that would be taxed at this rate of one fifth. The 1920 LDS edition replaced the colon by a comma, which obscures the difference between the general statement and the following list.
Interestingly, there is a characteristic difference between the general statement and all the items in the list—namely, the use of one in the general statement (“one fifth part”) but the indefinite article a in the list (“a fifth part”):
Oliver Cowdery’s second error in this passage was to initially omit the also that precedes the final item in the list. But he immediately corrected this error by partially overwriting the a that he had initially written and then by continuing to write the remainder of the word also without raising his quill. There is no change in the level of ink flow, nor is the additional lso inserted in any way; instead, it forms an unbroken continuation of Oliver’s inline writing. Thus the also was undoubtedly in the original manuscript.
Summary: The punctuation in the standard text for Mosiah 11:3 should make a clear distinction between “one fifth part of all they possessed” and the following list of items that were taxed at this rate; in addition, the last item in the list is preceded by the word also.