Links must have discernible text

Users who rely exclusively on a keyboard (and no mouse) to navigate a webpage can only click on links that can receive programmatic focus. A link that cannot receive programmatic focus is inaccessible to these users.

Like sighted users, screen reader users need to know where a link is pointing. Inner link text provides this information, though it won't get used if a screen reader can't access it.

Keyboard users, including visually impaired screen reader users or people who cannot use a mouse, can activate only the links and form elements that can receive programmatic focus. Any events activated exclusively by other types of focus, for example onmouseover events that depend on the mouse hover focus, are inaccessible to keyboard users. Only links and form elements receive keyboard focus by default. Modify elements that are not links or form components to receive focus by adding tabindex="0".

Fixing the problem

1. Ensure that all link names are accessible. It may be possible that the inner link text is not visible to a screen reader, that there are duplicate link labels, or that the link is not focusable.
2. Ensure all links can receive programmatic focus; for example, avoid device-specific events (for example, onmouseover).
3. To ensure all link text is visible to screen readers, link text cannot be hidden (e.g. with display: none or aria-hidden="true").
4. To ensure all links can receive programmatic focus, avoid device-specific Javascript events such as onmouseover(), mouseover(), hover(), onmouseout(), mouseout(). Replace these with device-independent events such as onfocus(), focus(), onblur(), or blur().
5. Do not modify the style of the links to suppress the change in style when a link is the object of programmatic focus. Modifying link styles removes the capability for sighted keyboard users to know where they are on the page. Furthermore, ensure you are creating real links using the a element with the href attribute.

The ARIA 1.1 Wiki Using aria-label for link purpose page provides the following example to describe the purpose of a link in HTML using the aria-label element:

<h4>Neighborhood News</h4>
<p>Seminole tax hike: Seminole city managers are proposing a 75% increase in  property taxes for the coming fiscal year.
<a href="taxhike.html" aria-label="Read more about Seminole tax hike">[Read more...]</a>
</p>
<p>Baby Mayor: Seminole voters elect the city's youngest mayor ever by voting in 3 year  old Willy "Dusty" Williams in yesterday's mayoral election.
<a href="babymayor.html" aria-label="Read more about Seminole's new baby mayor">[Read more...]</a>
</p>