Adobe 12020596 Supplement Manual page 109

Adobe Acrobat SDK
Adobe® Supplement to the ISO 32000
3.4.3 Cross-Reference Table
15. Acrobat viewers do not enforce the restriction on object numbers existing in more than one
subsection; they use the entry in the first subsection where the object number is encountered.
However, overlap is explicitly prohibited in cross-reference streams in PDF 1.5.
16. Acrobat 6.0 and later do not use the free list to recycle object numbers; new objects are assigned new
numbers.
17. Acrobat viewers do not raise an error in cases where there are gaps in the sequence of object numbers
between cross-reference subsections. The missing object numbers are treated as free objects.
3.4.4 File Trailer
18. Acrobat viewers require only that the
the file.
3.4.6 Object Streams
19. When creating or saving PDF files, Acrobat 6.0 limits the number of objects in individual object streams
to 100 for linearized files and 200 for non-linearized files.
3.4.7 Cross-Reference Streams (Cross-Reference Stream Dictionary)
20.
FlateDecode
These viewers also support unencoded cross-reference streams.
3.4.7 Cross-Reference Streams (Compatibility with PDF 1.4)
21. Byte addresses can be as large as needed to address an arbitrarily large PDF file, regardless of the
implementation limit for PDF integers in general.
3.5 Encryption
22. An option to use an unpublished algorithm was needed because of an export requirement of the U.S.
Department of Commerce. This requirement no longer exists. Acrobat 7.0 does not use this algorithm
to encrypt documents, although it can decrypt files that are encrypted with the algorithm.
23. Acrobat viewers will fail to open a document encrypted with a
the viewer does not understand.
24. Security handlers are responsible for protecting the value of
security handlers do not provide this protection.
3.5.2 Standard Security Handler (Standard Encryption Dictionary)
25. Acrobat viewers implement this limited mode of printing as "Print As Image, " except on UNIX systems,
where this feature is not available.
%%EOF
is the only filter supported by Acrobat 6.0 and later viewers for cross-reference streams.
Implementation Notes to the PDF Reference, sixth edition
marker appear somewhere within the last 1024 bytes of
value defined in a version of PDF that
V
from tampering if needed. Acrobat
EFF
Implementation Notes
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