Japan DAISY Consortium

JDC101, 1-1-61 Wakaba-cho, Chofu-shi,

Tokyo 182-0003, Japan

TEL: +81-3-5384-7207 FAX: +81-3-5384-7207

who produce DAISY textbooks in Japan. We are thus practical rather than theoretical or political.

The historical purpose of introducing ruby to Japanese typesetting practice was

probably to help those who could not read difficult CJK ideographic characters. Ruby

indeed helps such people. However, we have observed that ruby also hampers

accessibility. First, existing text-to-speech implementations do not work well for

documents containing ruby. Second, the typical rendering of ruby is hard to read for

low-vision and dyslexic people.

Making ruby accessible is a challenge. It is necessary to improve browser

implementations, and it is also necessary to improve HTML documents and CSS style

sheets.

that in the near future relevant stakeholders can coordinate and take up the necessary

technical work, both on specifications and more importantly on implementations, to

improve the accessibility of Japanese on the Web.

Current status of ruby accessibility

1) T2S

As of 2021, T2S does not work well for documents containing ruby. We created a wiki

That page is restricted to user requirements and thus does not consider possible

enhancements to current implementations. Here we would like to point out that the

generation of accessibility trees requires special treatment of ruby. Simply stripping tags

supplemental information (in which case both should be read), as heuristics cannot

reliably determine that.

2) Dyslexia

Some dyslexic people cannot separate base characters and ruby. Thus, a base character

with associated ruby looks like an unknown character having a strange radical to them.

To overcome this problem, it is important to widen the gap between base characters

and ruby. But this is not possible in most browsers except Firefox. The use of a different

color for ruby is also helpful and is fortunately supported by most browsers.

3) Low vision

Ruby is much smaller than normal text. Ruby is thus difficult for low-vision people to

rather than in the document source (see the text-transform property of CSS, currently

only supported in Firefox), we can make ruby easier for low-vision people to read

without hampering T2S.

It is also possible to change the font size of ruby depending on user preferences. Prof.

Nakano of Keio University reported that low-vision students prefer ruby long in height.

4) Textual fallback

Although visual rendering of ruby is expected to put the ruby in parallel to the base, the

textual or linear fallback of ruby is often required. Such fallback is used for metadata,

user interface components (see an EPUB issue), and so forth. When mono ruby is

attached to a sequence of base characters, it is unfortunately too common to see ruby

annotated text in many ways: showing or hiding some or all annotations; inlining them

in addition to, or in place of, the base text; and varying their typesetting style (mono vs

jukugo) and spacing. Different presentations can be appropriate for different reading

levels, reading preferences, and disabilities.

Unlike printed materials, IT technology, in theory, allows on-the-fly switching between

rendering styles, but such switching is not practically realized.

6) Conversion to braille

When assistive technology converts HTML or EPUB to Japanese braille, just as in the

in the accessibility tree or DOM tree. It then becomes easier to use both the base and

ruby for choosing the most appropriate braille.

Member of the Committee on Services for Persons with Disabilities, Japan Library Association

Global Chair of the ICTA/Rehabilitation International