SECTION 1.3
31
Related Publications
patibility with PDF documents that may include JavaScript segments to verify a
requirement. Before this feature was added, JavaScript was the only way to per-
form such requirement-checking. The feature ensures that either the JavaScript
segment verifies the requirement or a named handler verifies the requirement.
1.2.6 General Features
Additions to PDF 1.7 provide more cross-platform and cross-application stability,
by providing encoding information for strings and file names:
•
The clarification of string types to describe the encodings used for strings.
Throughout the entire PDF Reference, any uses of the string type are replaced
with one of the more specific string types. This clarification does not require
changes to PDF consumer applications. Instead, it provides a clearer under-
standing of the encoding supported by each PDF string entry. This understand-
ing can be especially important when comparing strings in a PDF document to
strings in an external source, such as an XML document or 3D artwork.
•
The ability to specify file names using Unicode in addition to specifying file
names using the standard encoding for the platform on which the document is
being viewed. This feature reduces problems in decoding file path names that
have been encoded on a different platform or in a different language.
1.2.7 PDF Reference Changes
This release of the
PDF Reference
includes clarifications not related to new fea-
tures or additional capabilities:
•
A description of the formulas for all blend modes.
•
An explanation of the TaggedPDF representation of nested table of contents
entries or list entries.
1.3 Related Publications
PDF and the PostScript page description language share the same underlying
Adobe imaging model. A document can be converted straightforwardly between
PDF and the PostScript language; the two representations produce the same out-
put when printed. However, PostScript includes a general-purpose programming
language framework not present in PDF. The
PostScript Language Reference
is the
comprehensive reference for the PostScript language and its imaging model.