Should you define an abbreviation more than once with the <abbr> tag?

Question

If I have an article or blog post and I have an abbreviation or abbreviation such as SAD (Seasonal Affective Disorder), should I do this every time the SAD abbreviation appears in the document?

<abbr title="Seasonal Affective Disorder">SAD</abbr> 

If you only define it once, is it necessary to do it the first time the abbreviation appears, or will it be the third or fourth time?

Answer 1

According to the Wikipedia style guide, you should only explain the abbreviation once. I would extend this to your case, and only use the abbreviation at the first appearance.

Answer 2

It depends on how the document is structured and how you expect people to come and read the document.

For example, if there is several anchor in the document, and the user can go to the middle of the page from another page or jump from the page at the top of the page, then it would be better to use <abbr> in each case ... so that the visitor gets an explanation.

Also, for accessibility, it would be better if users using screen readers hear the abbreviation.

Answer 3

Preferably you should define the acronym when you use it, however, its definition in the document is also acceptable.

Alternatively, to simplify the definition, you could assign the specified string to the php variable and use it to output html if it is actually used.

Edit: From an SEO perspective, you would prefer to change the first occurrence, since the first occurrence is what many search engines use to assign specific characteristics to a page.

Answer 4

The first appearance should be explained. Criterion 9.3 from the Accessiweb Link List Generalizes It Well (Test No. 2 for abbreviations)

On each web page, does each abbreviation first appear with one of the following conditions?
- The abbreviation is provided with its meaning as an adjacent reference.
- The abbreviation is implemented through a link linking to the page or location on the page, allowing to know its meaning
- The abbreviation is included in the link with the title attribute, allowing to know its meaning
- The meaning of the abbreviation is available in the glossary on the site
- The abbreviation is implemented using the abbr tag with a name that allows you to know its meaning

The appropriate WCAG 2.0 methods are sufficient (not normative, you can come with your own implementation):

• G97: providing abbreviation immediately after extended form
• G102: Providing an extension or explanation of abbreviation
• H28: Providing abbreviations with abbr and acronym
• H60: Using the link element to link to a glossary
• G55: binding to definitions
• G70: Providing a function to search for an online dictionary