When you provide alternate text for a hotspot in an image map, by default DITA2Go assigns the text to the alt attribute of the hotspot <area> tag. Some browsers, notably Internet Explorer, show the text in a tooltip when you mouse over the hotspot, whether the text is assigned to the alt attribute or to the title attribute of the hotspot <area> tag. Other browsers, notably Firefox, show the tooltip on mouse-over only if the text is assigned to the title attribute of the hotspot <area> tag.
To have DITA2Go use the title attribute of the hotspot <area> tag instead of the alt attribute for alternate text:
[Graphics] ; UseTitleForAlt = No (default) or Yes (use title attribute ; instead of alt for alternate text UseTitleForAlt=Yes
When UseTitleForAlt=Yes, DITA2Go assigns any alt text you specify for hotspots in image maps in the [GraphALT] section to the title attribute of the hotspot <area> tag, and includes an empty alt attribute for W3C validation.
Note: If you use the [GraphALT] section to assign alternate text to <img> tags (see §32.7 Providing (or omitting) alternate text for images), that text gets transferred to the <img> tag title attribute, and you lose the content of the <img> tag alt attribute.
UseTitleForAlt affects only alt content added for <img> tags and hotspot <area> tags in the [GraphALT] section, not alt content added for <img> tags via PI markers or via the [HTMLParaStyles] Alt property.