== Why is this an issue?
The ``++alt++``, ``++aria-label++`` and ``++aria-labelledby++`` attributes provide a textual alternative to an image.
It is used whenever the actual image cannot be rendered.
Common reasons for that include:
* The image can no longer be found
* Visually impaired users using a screen reader software
* Image loading is disabled, to reduce data consumption on mobile phones
It is also very important not to set an alternative text attribute to a non-informative value. For example, ``++++`` is useless as it doesn't give any information to the user. In this case, as for any other decorative image, it is better to use a CSS background image instead of an ``++++`` tag. If using CSS ``++background-image++`` is not possible, an empty ``++alt=""++`` is tolerated. See Exceptions below.
This rule raises an issue when:
* An ``++++`` element has no ``++alt++`` attribute.
* An ``++++`` element has no ``++alt++``, ``++aria-label++`` or ``++aria-labelledby++`` attribute or they hold an empty string.
* An ``++++`` element within an image map has no ``++alt++``, ``++aria-label++`` or ``++aria-labelledby++`` attribute.
* An ``++