Avoid causing content to blink |
WAI / WCAG 1.0 Priority 2 checkpoint 7.2
Issue Description The page contains the BLINK tag, which is a non standard tag.
How to fix Replace the BLINK tag with another formatting property that does not require the text to appear and disappear with no control given to the website visitor. Remember that the W3C (HTML Techniques for Web Content Accessibility Guidelines 1.0 [http://www.w3.org/TR/WCAG10-HTML-TECHS/#style-text] ) suggests not to use BLINK and neither MARQUEE.

If blinking effect is required, implement it using the css property 'text-decoration: blink'. In this way the end result will be the same, however:

- the website visitor can choose to disable CSS processing by the browser, and the blinking will stop;
- A better option is to provide more than one CSS style file linked to the page. It is still possible for most of the properties to remain the same (in the all the files) except for the 'text-decoration: blink'. In this way the visitor (using an up-to-date browser) can switch between the style files and choose the one that does everything that is needed, except for the blinking.
- the HTML file will contain valid code and will be smaller (as the blinking property will be written only once in the external style file).

Issue Explanation The BLINK tag will turn on and off its content. The user of the browser will in no way be able to stop this on/off behavior. This blinking behavior is very distracting to the eye, and will make it very difficult to concentrate on the task of reading the information in the page or in filling in the form contained in the page.

The consequences will be even more significant on users that suffer from cognitive disorders, as they will have a very hard time concentrating on the page content. Consider also users of screen magnifiers who may read a small portion of the page that overlaps with the blinking text. In these cases, a large part of the magnified screen will blink; again making it very hard for these users to concentrate on the task.

Consider that, in a sense, everyone is cognitively disabled when under stress. For example, when buying an e-ticket for a flight from a kiosk in a very noisy and crowded airport, with a long line of people waiting for the same kiosk, most people will be unable to fully concentrate on the task. A blinking element in the page will not help the user to complete the purchase.