Placeholder for information about ruby accessibility.
The document Rules for Simple Placement of Japanese Ruby has been moved here.
The information below about accessibility was removed from that document, and is retained here until it can be extended, at which point it will be published as a separate, accessibility-specific document.
Ruby plays a role in improving accessibility for people with visual impairments, and other sources of reading difficulties. Therefore, this section examines the relationship between ruby and accessibility.
視覚障害者などのアクセシビリティを向上させるためにルビは一定の役割を果たしている．そこで，アクセシビリティに関係するルビの問題について補足しておく．
Reading difficulties can be caused by a variety of factors, and therefore, requirements to improve accessibility also vary. For example, here are some common requirements:
読書が困難となる原因はさまざまであり，これに伴いアクセシビリティを向上させるために要求される要件も異なってくる．例えば，以下のような要求がある．
To accommodate young children who cannot read any kanji, general-ruby must be added to all kanji.
漢字がほとんど読めない子がいるので，すべての漢字にルビを付ける総ルビが必要となる．
As studies progress, a greater number of kanji is known. After having read general-ruby many times, ruby on difficult kanji only becomes sufficient. Therefore para-ruby on only some of the kanji is required.
学習が進むと読める漢字も増える．また，総ルビで何回か読んだあとでは，難しい漢字だけのルビでよいので，一部の漢字だけにルビを付けるパラルビが必要である．
Some people have difficulties in visually distinguishing between ruby characters and the base characters to which they are attached, and misread the combination as a different character altogether. There must be a display method that enables clearly distinguishing between the two. Also, for those who already know how to read the kanji, there must be a way to hide the ruby.
ルビと親文字との区別がつかず，別の文字と認識するケースがあるので，ルビと親文字がはっきり区別できるような表示方法が必要である．あるいは，漢字が読める人にとっては，かえってルビが余分なものとなる可能性もあるので，ルビを付けない方法も必要となる．
As inline parenthesised annotations can be used instead, there is no strong need for double-sided ruby.
括弧書きなどで代用できることから，両側のルビはそれほど必要としない．
Based on the above, we can gather the following ruby display requirements for accessibility:
上記の要求例から，アクセシビリティにとってのルビの表示要件としては，次のようなことが求められる．
Support for general-ruby is required.
総ルビが必要である．
Support for para-ruby is required. Moreover, as the number of kanji known increases with the level of studies, based on the content and on the level of the reader, it must be possible to only display ruby for kanji assigned to a particular school year (or later).
パラルビが必要である．なお，パラルビでは，学習の進行に伴い学ぶ漢字が増えていくので，コンテンツの内容や読者層に応じて，指定した学年以降で習う漢字についてルビを表示する必要がある．
Support for hiding ruby is required.
ルビなしが必要である．
Considering the cost of production, distribution, and of user management, it is necessary to support ruby-less display, general-ruby display, and para-ruby display with the same content.
製作コスト，配布コスト，利用者の管理コストを考慮すると，同一コンテンツで，総ルビ，パラルビ及びルビなしと表示し分けられる必要がある．
A method to clearly visually distinguish the ruby characters and their based characters, such as displaying them in different colors, is required.
ルビと親文字がはっきり区別できるようにルビの色を変える等の表示方法の工夫が必要である．