ruby textルビのテキスト。contains a ruby
text, an annotation closely associated with a passage of the
main text.本文の一部と密接な関連を持つ注釈（主に読み方）としてのルビテキストを含む。supplies a pointer to the
base being glossed by this ruby text.ルビテキストの対象へのポインタを示す。Enforce that eithertarget or both from and
to (or none) are used, but not
target in combination with either
from or to.When target= is present, neither from= nor to= should be.
Should point to a single rb or an element
that is inside an rb. To refer to multiple
elements or text nodes at once use from and
to.
points to the starting point of the span of text
being glossed by this ruby text.ルビテキストの対象範囲の始点を示す。Enforce the presence of to iff there
is a from.When from= is present, the to= attribute of is required.points to the ending point of the span of text
being glossed.ルビテキストの対象範囲の終点を示す。Enforce the presence of from iff there
is a to.When to= is present, the from= attribute of is required.
The word 大統領daitōryō
(president) is glossed character by character in hiragana to provide a pronunciation guide.
大統領
Where the place attribute is not provided on the rt
element, the default assumption is that the
ruby gloss is above where the text is horizontal, and to the
right of the text where it is vertical.