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12.3.2.3
Named Destinations
Instead of being defined directly with the explicit syntax shown in Table 151, a destination may be referred to
indirectly by means of a name object (PDF 1.1) or a byte string (PDF 1.2). This capability is especially useful
when the destination is located in another PDF document.
NOTE 1
A link to the beginning of Chapter 6 in another document might refer to the destination by a name, such as
Chap6 . begin, instead of by an explicit page number in the other document. Then, the location of the chapter in
the other document could change without invalidating the link. If an annotation or outline item that refers to a
named destination has an associated action, such as a remote go-to action (see 12.6.4.3, “Remote Go-To
Actions”) or a thread action (12.6.4.6, “Thread Actions”), the destination is in the file specified by the action’s F
entry, if any; if there is no F entry, the destination is in the current file.
In PDF 1.1, the correspondence between name objects and destinations shall be defined by the Dests entry in
the document catalogue (see 7.7.2, “Document Catalog”). The value of this entry shall be a dictionary in which
each key is a destination name and the corresponding value is either an array defining the destination, using
the syntax shown in Table 151, or a dictionary with a D entry whose value is such an array.
NOTE 2
The latter form allows additional attributes to be associated with the destination, as well as enabling a go-to
action (see 12.6.4.2, “Go-To Actions”) that shall be used as the target of a named destination.
In PDF 1.2 and later, the correspondence between strings and destinations may alternatively be defined by the
Dests entry in the document’s name dictionary (see 7.7.4, “Name Dictionary”). The value of this entry shall be
a name tree (7.9.6, “Name Trees”) mapping name strings to destinations. (The keys in the name tree may be
treated as text strings for display purposes.) The destination value associated with a key in the name tree may
be either an array or a dictionary, as described in the preceding paragraph.
NOTE 3
The use of strings as destination names is a PDF 1.2 feature. If compatibility with earlier versions of PDF is
required, only name objects may be used to refer to named destinations. A document that supports PDF 1.2
can contain both types. However, if backward compatibility is not a consideration, applications should use the
string form of representation in the Dests name tree.
12.3.3
Document Outline
A PDF document may contain a document outline that the conforming reader may display on the screen,
allowing the user to navigate interactively from one part of the document to another. The outline consists of a
tree-structured hierarchy of outline items (sometimes called bookmarks), which serve as a visual table of
contents to display the document’s structure to the user. The user may interactively open and close individual
items by clicking them with the mouse. When an item is open, its immediate children in the hierarchy shall
become visible on the screen; each child may in turn be open or closed, selectively revealing or hiding further
parts of the hierarchy. When an item is closed, all of its descendants in the hierarchy shall be hidden. Clicking
the text of any visible item activates the item, causing the conforming reader to jump to a destination or trigger
an action associated with the item.
The root of a document’s outline hierarchy is an outline dictionary specified by the Outlines entry in the
document catalogue (see 7.7.2, “Document Catalog”). Table 152 shows the contents of this dictionary. Each
individual outline item within the hierarchy shall be defined by an outline item dictionary (Table 153). The items
at each level of the hierarchy form a linked list, chained together through their Prev and Next entries and
accessed through the First and Last entries in the parent item (or in the outline dictionary in the case of top-
[ page /FitBV left ]
(PDF 1.1) Display the page designated by page, with the horizontal
coordinate left positioned at the left edge of the window and the
contents of the page magnified just enough to fit the entire height of its
bounding box within the window. A null value for left specifies that the
current value of that parameter shall be retained unchanged.
Table 151 – Destination syntax (continued)
Syntax
Meaning
