CHAPTER 10
910
Document Interchange
The following items can be children of an annotation element:
•
Object references (see “PDF Objects as Content Items” on page 868) to one or
more annotation dictionaries
•
Optionally, one or more content items (such as marked-content sequences) or
other ILSEs (except other annotations) associated with the annotations
If an
Annot
element has no children other than object references, its rendering is
defined by the appearance of the referenced annotations, and its text content is
treated as if it were a
Span
element. It may have an optional
BBox
attribute; if sup-
plied, this attribute overrides the rectangle specified by the annotation dictio-
nary’s
Rect
entry.
If the
Annot
element has children that are content items, those children represent
the displayed form of the annotation, and the appearance of the associated anno-
tation may also be applied (for example, with a
Highlight
annotation).
There can be multiple children that are object references to different annotations,
subject to the constraint that the annotations must be the same except for their
Rect
entry. This is much the same as is done for the
Link
element; it allows an an-
notation to be associated with discontiguous pieces of content, such as line-
wrapped text.
Ruby and Warichu Elements
Ruby text is a side note, written in a smaller text size and placed adjacent to the
base text to which it refers. It is used in Japanese and Chinese to describe the pro-
nunciation of unusual words or to describe such items as abbreviations and logos
.
Warichu text is a comment or annotation, written in a smaller text size and for-
matted onto two smaller lines within the height of the containing text line and
placed following (inline) the base text to which it refers. It is used in Japanese for
descriptive comments and for ruby annotation text that is too long to be aestheti-
cally formatted as a ruby.