Previous Next

                                              855
     SECTION 10.6                                                         Logical Structure



     marked-content sequence S3 and the marked-content point P1 are both part of
     sequence S2, and S2, S3, and P1 are all part of sequence S1.

     Example 10.5

        /S1 BMC
           … Clipping path …
           /S2 BMC
              /S3 BMC
              EMC
              /P1 DP
           EMC
        EMC

     In Example 10.6, marked-content sequences S1 and S4 are marked clipping
     sequences because the only object they contain is a clipping path. Hence the
     clipping path is part of sequences S1 and S4; S3 is part of S2; and S2, S3, and S4 are
     all part of S1.

     Example 10.6

        /S1 BMC
           /S2 BMC
              /S3 BMC
              EMC
           EMC

          /S4 BMC
             … Clipping path …
          EMC
        EMC


10.6 Logical Structure

     PDF’s logical structure facilities (PDF 1.3) provide a mechanism for incorporating
     structural information about a document’s content into a PDF file. Such in-
     formation might include, for example, the organization of the document into
     chapters and sections or the identification of special elements such as figures,
     tables, and footnotes. The logical structure facilities are extensible, allowing
     applications that produce PDF files to choose what structural information to
     include and how to represent it, while enabling PDF consumers to navigate a file
     without knowing the producer’s structural conventions.

Previous Next