HTML and CSS Reference
In-Depth Information
3.10. The <bdo> Tag
As we mentioned earlier, the authors of the HTML 4 standard made a
concerted effort to include standard ways that web agents (browsers) are
supposed to treat and display the many different human languages and
dialects. Accordingly, the HTML 4 standard and its progeny, XHTML, con-
tain the universal
dir
and
lang
attributes that let you explicitly advise
the browser that the whole document or specific tagged segments within
it are in a particular language. These language-related attributes, then,
may affect some display characteristics; for example, the
dir
attribute
tells the browser to write the words across the display from either left to
right (
dir=ltr
), as for most Western languages, or right to left (
dir=rtl
),
as for many Asian languages.[
The dir attribute, 3.6.1.1
]
[
The lang attrib-
The various Unicode and ISO standards for language encoding and dis-
play may conflict with your best intentions. In particular, the contents of
some other documents, such as a Multipurpose Internet Mail Extension
(MIME)-encoded file, may already be properly formatted, and your doc-
ument may misadvise the browser to undo that encoding. Hence, the
HTML 4 and XHTML standards have the
<bdo>
tag. With it, you override
any current and inherited
dir
specifications. And with the tag's required
dir
attribute, you definitively specify the direction in which the tag's con-
tents should be displayed.
For example,
Figure 3-5
shows how Internet Explorer handles the follow-
ing HTML fragment containing a
<bdo>
redirection:
<bdo dir=rtl>This would be readable if in Chinese, perhaps.</bdo>
Back to the Western way of reading and writing.
