Why is there a ... after each post in our post history

Because a single line of a few characters are devoted to the preview of the post.

Usually the post continues.

So, after a set number of characters, you get a ... to show the post continues.

I think ... is standard behind everything, whether the post is longer than the characters allowed in the preview or not. To only put it after a certain number of characters would probably be difficult to program, so they all get the ...

quote:

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Even really short posts have ... after it.

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Right. So instead of writing additional script, the first line has ... after it.

Still falls in my theory. :)

there's a word for "..."

It's called an ellipsis