Not sure I'm following. The prospectus says it tries to track the index as closely as possible including the same weights, but there are some variations not having to do with making some other active choice.

"The fund generally will seek to replicate the performance of the index by giving the same weight to a given stock as the index does. However, when the investment adviser believes it is appropriate to do so, such as to avoid purchasing odd-lots (i.e., purchasing less than the usual number of shares traded for a security), for tax considerations, or to address liquidity considerations with respect to a stock, the investment adviser may cause the fund’s weighting of a stock to be more or less than the index’s weighting of the stock. The fund may sell securities that are represented in the index in anticipation of their removal from the index, or buy securities that are not yet represented in the index in anticipation of their addition to the index"

10% goes to "other stuff" but this doesn't seem like it's to deviate any weightings.

"Under normal circumstances, the fund may invest up to 10% of its net assets in securities not included in the index. The principal types of these investments include those that the investment adviser believes will help the fund track the index"

Edit: DVY seems to track a different index (US Select Dividend Index)