The Caption dialog creates / edits captions on images with options for text color, padding and alignment and caption container margin, padding, background color and border styling.

In its simplest form, this consists of a parent <span> wrapped around the source image and an additional text <span>, eg:

<span class="wf_caption" style="max-width: 128px; display: block; width: 100%; border: 1px solid #000000; background-color: #eeeeee;">
<img alt="strawberry" src="" />
<span style="text-align: center; display: block;">strawberry</span>