SECTION 10.6
863
Logical Structure
A structure element dictionary can include one or more marked-content se-
quences as content items by referring to them in its
K
entry (see Table 10.10). This
reference can have two forms:
•
A dictionary object called a
marked-content reference.
contents of this type of dictionary, which specifies the marked-content identifi-
er, as well other information identifying the stream in which the sequence is
contained. Example 10.8 illustrates the use of a marked-content reference to the
marked-content sequence shown in Example 10.7.
•
An integer that specifies the marked-content identifier. This can be done in the
common case where the marked-content sequence is contained in the content
stream of the page that is specified in the
Pg
entry of the structure element dic-
tionary. Example 10.9 shows a structure element that has three children: a
marked-content sequence specified by a marked-content identifier, as well as
two other structure elements.
Example 10.8
1 0 obj
<< /Type /StructElem
/S /P
/P …
/K << /Type /MCR
/Pg 2 0 R
/MCID 0
>>
>>
endobj
% Structure element
% Structure type
% Parent in structure hierarchy
% Page containing marked-content sequence
% Marked-content identifier
TABLE 10.11 Entries in a marked-content reference dictionary
KEY
TYPE
VALUE
Type
name
dictionary
(Required)
The type of PDF object that this dictionary describes; must be
MCR
for a marked-content reference.
(Optional; must be an indirect reference)
The page object representing the page
on which the graphics objects in the marked-content sequence are rendered.
This entry overrides any
Pg
entry in the structure element containing the
marked-content reference; it is required if the structure element has no such en-
try.
Pg