Adobe Acrobat SDK
Implementation Notes
Adobe® Supplement to the ISO 32000
Implementation Notes to the PDF Reference, sixth edition 107
character, preceding two hexadecimal digits. Thus, a 3-character name A-space-B can now be written
as /A#20B (since 20 is the hexadecimal code for the space character). This means that the name /A#B is
no longer valid, since the number sign is not followed by two hexadecimal digits. A name object with
this value must be written as /A#23B, since 23 is the hexadecimal code for the character #.
4. In cases where a PostScript name must be preserved or where a string is permitted in PostScript but
not in PDF, the Acrobat Distiller application uses the # convention as necessary. When an Acrobat
viewer generates PostScript, it inverts the convention by writing a string where permitted or a name
otherwise. For example, if the string (Adobe Green) were used as a key in a dictionary, Distiller would
use the name /Adobe#20Green and the viewer would generate (Adobe Green).
5. In Acrobat 4.0 and earlier versions, a name object being treated as text is typically interpreted in a host
platform encoding, which depends on the operating system and the local language. For Asian
languages, this encoding may be something like Shift-JIS or Big Five. Consequently, it is necessary to
distinguish between names encoded this way and ones encoded as UTF-8. Fortunately, UTF-8
encoding is very stylized and its use can usually be recognized. A name that does not conform to UTF-8
encoding rules can instead be interpreted according to host platform encoding.
3.2.7 Stream Objects
The following note is associated with the description of the
DecodeParms
key in Table 3.4.
7. Acrobat viewers accept the name
DP
as an abbreviation for the
DecodeParms
key in any stream
dictionary. If both
DP
and
DecodeParms
entries are present,
DecodeParms
takes precedence.
3.2.9 Indirect Objects
8. Acrobat viewers require that the name object used as a key in a dictionary entry be a direct object; an
indirect object reference to a name is not accepted.
3.3 Filters
9. Acrobat viewers accept the abbreviated filter names shown in table titled “Abbreviations for standard
filter names” in addition to the standard ones. These abbreviated names are intended for use only in
the context of inline images (see Section 4.8.6, “Inline Images”), they should not be used as filter names
in any stream object.
Abbreviations for standard filter names
STANDARD FILTER NAME
ABBREVIATION
ASCIIHexDecode
AHx
ASCII85Decode
A85
LZWDecode
LZW
FlateDecode
(PDF 1.2)
Fl
(uppercase F, lowercase L)
RunLengthDecode
RL
