::-ms-expand

Non-standard
This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

Summary

The ::-ms-expand CSS pseudo-element represents the button within a <select> that opens or closes the drop-down menu that displays the <option>s. It often normally looks like a triangle that points downward.

Specification

Not part of any specification.

Microsoft has a description on MSDN.

Document Tags and Contributors

 Contributors to this page: mrenty, kscarfone, cvrebert
 Last updated by: mrenty,