Which type of punctuation signals the reader that words have been omitted from a direct quotation?

The punctuation that signals omitted words in a direct quotation is ellipsis points ( . . . ).

Here's an example:

> "I have a dream that my four little children will one day live in a nation . . . where they will not be judged by the color of their skin but by the content of their character." - Martin Luther King Jr.