In the HTML editor it is possible to embed images. However, only an additional "alt" text can be added, there is no field to add a title or an image caption.
The alt text is used for devices that can not display the images (accessibility feature). The title attribute is normally rendered on mouse-over to display additional information.
In HTML5, the image can be wrapped in a figure element and enriched with a figcaption. The goal of this issue is to enable this title and caption feature in the HTML editor.
There are some nasty problems with CSS classes. The styles selectable on the image element will not work when enabling the caption. In this case, the image must be selected and one of the default left-center-right alignment styles must be uses.