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Implementation Notes
This chapter provides notes on the implementation of Acrobat 9. The notes are listed in the order of the
sections to which they refer in the main text. There are two parts to the implementation notes:
Implementation Notes to the PDF Reference, sixth edition:
These notes appear in Appendix H,
“Compatibility and Implementation Notes” of
PDF Reference, sixth edition, version 1.7
. Two of the notes,
notes 77 and 156, are significantly modified.
Implementation Notes to Adobe Extensions to ISO 32000:
These notes remark on Acrobat’s
implementation of the extensions to the PDF language, as documented in Part I, “Extensions to the PDF
Specification”, of this guide. The implementation notes for the Adobe extensions begin on
page 130
.
Note:
This guide uses italics to identify information not intended for inclusion in the PDF specification. For
convenience, the phrase
BaseVersion 1.7, Adobe ExtensionLevel 3
is shortened to
ExtensionLevel 3
throughout this document.
Implementation Notes to the PDF Reference, sixth edition
These notes originally appeared in the
PDF Reference.
See that document for the context of each note.
1.2 Introduction to PDF 1.7 Features
This note applies to the first paragraph in this section.
1. The native file formats of Acrobat products are PDF 1.2 for Acrobat 3.0, PDF 1.3 for Acrobat 4.0, PDF 1.4
for Acrobat 5.0, PDF 1.5 for Acrobat 6.0, PDF 1.6 for Acrobat 7.0, and PDF 1.7 for Acrobat 8.0.
Beginning with Acrobat 8.1, the native file formats for Acrobat products are extensions relative to a
base version of PDF. The extensions are described in the
Adobe Supplement to ISO 32000
(this
document). For base version 1.7, the following is a list of each Adobe extension level and the
applications (shown in parentheses) supported by that extension level.
●
ISO 32000: XFA 2.5 and PDF 1.7 (Acrobat 8.0, LiveCycle, SAP P3B)
●
Adobe Extension Level 1: PRC and XFA 2.6 (Acrobat 8.1, LiveCycle ES), the addition of PRC for 3D
data.
●
Adobe Extension Level 2: XFA 2.7 (SAP P3C)
●
Adobe Extension Level 3: XFA 2.8 (Acrobat 9.0, LiveCycle ES 8.2 ) and all the information contained
in this document concerning additions to the PDF language.
3.1.2 Comments
2. Acrobat viewers do not preserve comments when saving a file.
3.2.4 Name Objects
3. In PDF 1.1, the number sign character (#) could be used as part of a name (for example, /A#B), and the
specifications did not specifically prohibit embedded spaces (although Adobe producer applications
did not provide a way to write names containing them). In PDF 1.2, the number sign became an escape
