…
Three dots in a single gem — and the line never splits them.
The typographic ellipsis is a single character, its inner spacing calculated by the typeface's designer. Three full stops typed in a row sit tighter — and can be split by a line break.
As one character it travels whole, counts as one symbol and answers to a single Backspace. The entity is ….
Wrong: once upon a time... (three loose, breakable dots)
Right: once upon a time… (one gem, three dots cut together)