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CHAPTER 10                                                  Document Interchange



• A marked clipping sequence is a marked-content sequence that contains at least
  one clipping object and no visible graphics objects.
• Clipping objects and marked clipping sequences are considered part of an
  enclosing marked-content sequence only if it is a marked clipping sequence.
• Invisible graphics objects and empty marked-content elements are always con-
  sidered part of an enclosing marked-content sequence, regardless of whether it
  is a marked clipping sequence.
• The q (save) and Q (restore) operators may not occur within a marked clipping
  sequence.

Example 10.4 illustrates the application of these rules. Marked-content sequence
S4 is a marked clipping sequence because it contains a clipping object (clipping
path 2) and no visible graphics objects. Clipping path 2 is therefore considered
part of sequence S4. Marked-content sequences S1, S2, and S3 are not marked
clipping sequences, since they each include at least one visible graphics object.
Thus, clipping paths 1 and 2 are not part of any of these three sequences.

Example 10.4

  /S1 BMC
     /S2 BMC
        /S3 BMC
           0 0 m
           100 100 l
           0 100 l W n                  % Clipping path 1

          0 0 m
          200 200 l
          0 100 l f                     % Filled path
        EMC

       /S4 BMC
          0 0 m
          300 300 l
          0 100 l W n                   % Clipping path 2
       EMC
    EMC
    100 100 10 10 re f                  % Filled path
  EMC

In Example 10.5, marked-content sequence S1 is a marked clipping sequence
because the only graphics object it contains is a clipping path. Thus, the empty

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