HTML <rp> Tag

The <rp> element is a semantic HTML tag used specifically in conjunction with ruby annotations, which are small texts typically rendered above or beside base text to provide pronunciation, translation, or other annotations. The main purpose of <rp> is to provide fallback content for browsers that do not support ruby annotations.

When a browser cannot display ruby text (usually enclosed in the <rt> element), any content inside <rp> will be displayed instead. This ensures that users can still understand the intended annotation even if their browser does not support the ruby layout. Typically, <rp> is used to wrap characters like parentheses around the ruby text, such as ( and ), to visually indicate the presence of a ruby annotation.

For example, in a sentence with Japanese text and its pronunciation:

<ruby>
  漢 <rp>(</rp><rt>かん</rt><rp>)</rp>
  字 <rp>(</rp><rt>じ</rt><rp>)</rp>
</ruby>

In browsers that support ruby annotations, the pronunciation (かん and じ) appears above the corresponding kanji (漢 and 字). In browsers that do not support ruby, the <rp> elements display the parentheses to indicate that there is a pronunciation or annotation for the text.