Ensure alternative text for image links is informative

[New] - 3/18/2018

[Issue]When screen reader users navigate to "i" which opens a tooltip, screen reader does not announce the name of this content. There is no alternative text for this image link.

[User Impact]Screen reader users not able to identify the content.[Code]

<a id="id1b" class="sakai-wicket-iconwithtooltip" href="#id1a" rel="#id1a" title="" style=""><img src="/library/image/silk/information.png"></a>

[Expected behavior]Developers must ensure that they provide informative alternative text for image link which helps assistive technologies users to understand the content.Here, developers need to provide the role of the tooltip and it needs to reference through "aria-describedby" before or at the time tooltip is displayed.

[Sample Code]

<a id="id1b" class="sakai-wicket-iconwithtooltip" href="#id1a" rel="#id1a" title="" style=""><img alt="Privacy setting for birthday" title="Privacy setting for birthday"src="/library/image/silk/information.png"></a>