How to indicate elision in a quotation?

Old question, but it was the first to come up on my google search. If anyone is still looking, the \textelp{} command from the csquotes package provides exactly the functionality requested:

\documentclass{article}
\usepackage{csquotes}

\begin{document}

\enquote{The csquotes package provides elipses, \textelp{} as well as smart quoting.}

\end{document}

How about something like the following?

\newcommand*\elide{\textup{[\,\dots]}}

Elision is the omission of one or more sounds. If it can be applied as a typographical term, I am not sure. However, since an ellipsis represents dot-dot-dot an ellipsis within square brackets named an elision seems like a good idea.

Both \dots and \ldots would print the same. They are both defined the same way in TeX.

 \mathchardef\ldotp="613A % ldot as a punctuation mark
 \def\ldots{\mathinner{\ldotp\ldotp\ldotp}}
 \def\dots{\relax\ifmmode\ldots\else$\m@th\ldots\,$\fi}

The reason that Math mode is used is to ensure that the normal rules for spacing are not applied here.

An ellipsis within a square bracket looks ugly! It is an intrusion within the text. Bringhurst suggests that normally an ellipsis should be spaced fore-and-aft to separate it from the text, but when it combines with other punctuation, the leading space disappears and the other punctuation follows. So to define the command fully, one needs to take all aspects into consideration.

TH's suggestion is possibly the best you can get, I would just add xspace, in case someone sticks an elision at the end of the sentence or starts a new sentence after it.

 \newcommand*\elide{\textup{[\,\dots]}\xspace}

This should have gone probably as a comment rather than an answer, but I thought you would find the TeX code of interest.