SECTION 8.2
589
Document-Level Navigation
A
collection dictionary
specifies the viewing and organizational characteristics of
portable collections. If this dictionary is present in a PDF document, the user in-
terface presents the document as a portable collection. The
EmbeddedFiles
name
tree specifies file attachments (see Section 3.10.3, “Embedded File Streams).
When a PDF 1.7-compliant viewer application first opens a PDF document con-
taining a collection, it must display the contents of the initial document, along
with a list of the documents present in the
EmbeddedFiles
name tree. The docu-
ment list must include the additional document information specified by the col-
lection schema. The initial document can be the container PDF or one of the
embedded documents.
The page content in the initial document typically contains information that
helps the viewer understand what is contained in the collection, such as a title
and an introductory paragraph.
The file attachments comprising a collection are located in the
EmbeddedFiles
name tree. All attachments in that tree are in the collection; any attachments not
in that tree are not.
TABLE 8.6 Entries in a collection dictionary
KEY
TYPE
VALUE
Type
name
dictionary
(Optional) The type of PDF object that this dictionary describes; if
present, must be
Collection
for a collection dictionary.
(Optional) A collection schema dictionary (see Table 8.7). If absent,
the PDF viewer application may choose useful defaults that are
known to exist in a file specification dictionary, such as the file
name, file size, and modified date.
(Optional) A string that identifies an entry in the
EmbeddedFiles
name tree, controlling the document that is initially presented in
the user interface. If the
D
entry is missing or in error, the initial
document is the one that contains the collection dictionary.
Schema
D
byte string