Window Styles

.iframe

<a class="iframe" href="pick your link">
iframe</a>

.iframeshort

<a class="iframeshort" href="pick your link">
iframeshort</a>

.iframepdf

<a class="iframepdf" href="pick your link">
iframepdf</a>

When picking a link, use the wysiwug's built in selective process, because when doing so to select an internal link/asset, the system will add in a /render/file.act?path=, which will maintain the connection to the selected link/asset, even if the destination link/asset is moved.