The dots are called ellipses. They indicate an omission of a word or phrase.
Example sentence - The omission of the facts was not acceptable to the grand jury.
Her omission of crucial details from her report caused confusion among the team members.
Note the correct spelling: "omission" contains two "s"s but only one "m". Here is a sample sentence: I noticed a critical omission in your instructions.
4 periods are used when an omission ends a sentence.
a contraction
The omission of an important number was an unintended mistake.
The omission of his name from the movie credits is regrettable. He lied by omission when he failed to say that he had in fact been there that night. It was an omission to not give the winner a prize.
Ellipses are used to show an intentional omission of words or phrases. See links.
You can denote the intentional omission of words by using an ellipsis ("...") to show where words have been left out in a sentence or quotation. This indicates that the omission was intentional and not a mistake.
Example: And he to England shall along with you. - Hamlet ellipse - deliberate omission of a word or of words which are readily implied by the context.
The word for the omission of a sound in speech is "elision." Elision refers to the removal or omission of certain sounds or syllables in spoken language, often to aid in pronunciation or to make speech more fluid.