Ellipsis (AP's rules)

ellipsis ( ... ) In general, treat an ellipsis as a three-letter word, constructed with three periods and two spaces, as shown here.
Use an ellipsis to indicate the deletion of one or more words in condensing quotes, texts and documents. Be especially careful to avoid deletions that would distort the meaning.
An ellipsis also may be used to indicate a thought that the speaker or writer does not complete. Substitute a dash for this purpose, however, if the context uses ellipses to indicate that words actually spoken or written have been deleted.
Brief examples of how to use ellipses are provided after guidelines are given. More extensive examples, drawn from the speech in which President Richard Nixon announced his resignation, are in the sections below marked CONDENSATION EXAMPLE and QUOTATIONS.
SPACING REQUIREMENTS: In some computer editing systems the thin space must be used between the periods of the ellipsis to prevent them from being placed on two different lines when they are sent through a computer that handles hyphenation and justification.
Leave one regular space – never a thin – on both sides of an ellipsis: I ... tried to do what was best.
PUNCTUATION GUIDELINES: If the words that precede an ellipsis constitute a grammatically complete sentence, either in the original or in the condensation, place a period at the end of the last word before the ellipsis. Follow it with a regular space and an ellipsis: I no longer have a strong enough political base. ...
When the grammatical sense calls for a question mark, exclamation point, comma or colon, the sequence is word, punctuation mark, regular space, ellipsis: Will you come? ...
When material is deleted at the end of one paragraph and at the beginning of the one that follows, place an ellipsis in both locations.
CONDENSATION EXAMPLE: Here is an example of how the spacing and punctuation guidelines would be applied in condensing President Richard Nixon's resignation announcement:
Good evening. ...
In all the decisions I have made in my public life, I have always tried to do what was best for the nation. ...
... However, it has become evident to me that I no longer have a strong enough political base in Congress.
... As long as there was a base, I felt strongly that it was necessary to see the constitutional process through to its conclusion, that to do otherwise would be ... a dangerously destabilizing precedent for the future.
QUOTATIONS: In writing a story, do not use ellipses at the beginning and end of direct quotes:
"It has become evident to me that I no longer have a strong enough political base," Nixon said.
Not "... it has become evident to me that I no longer have a strong enough political base ... ," Nixon said.
SPECIAL EFFECTS: Ellipses also may be used to separate individual items within a paragraph of show business gossip or similar material. Use periods after items that are complete sentences.