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SECTION 5.8 Embed ded Font Programs
KEY TYPE VALUE
Length2 integer (Required for Type 1 fonts) The length in bytes of the encrypted portion of the Type 1 font
program (see below) after it has been decoded using the filters specified by the stream’s Fil-
ter entry.
Length3 integer (Required for Type 1 fonts) The length in bytes of the fixed-content portion of the Type 1
font program (see below) after it has been decoded using the filters specified by the stream’s
Filter entry. If Length3 is 0, it indicates that the 512 zeros and cleartomark have not been in-
cluded in the FontFile font program and must be added.
Subtype name (Required if referenced from FontFile3; PDF 1.2) A name specifying the format of the embed-
ded font program. The name must be Type1C for Type 1 compact fonts, CIDFontType0C for
Type 0 compact CIDFonts, or OpenType for OpenType fonts. When additional font formats
are added to PDF, more values will be defined for Subtype.
Metadata stream (Optional; PDF 1.4) A metadata stream containing metadata for the embedded font pro-
gram (see Section 10.2.2, “Metadata Streams”).
A standard Type 1 font program, as described in the Adobe Type 1 Font Format
specification, consists of three parts: a clear-text portion (written using PostScript
syntax), an encrypted portion, and a fixed-content portion. The fixed-content
portion contains 512 ASCII zeros followed by a cleartomark operator, and per-
haps followed by additional data. Although the encrypted portion of a standard
Type 1 font may be in binary or ASCII hexadecimal format, PDF supports only the
binary format. However, the entire font program may be encoded using any filters.
Example 5.14 shows the structure of an embedded standard Type 1 font.
Example 5.14
12 0 obj
<< /Filter /ASCII85Decode
/Length 41116
/Length1 2526
/Length2 32393
/Length3 570
>>
stream
,p>`rDKJj'E+LaU0eP.@+AH9dBOu$hFD55nC
… Omitted data …
JJQ&Nt')<=^p&mGf(%:%h1%9c//K(/*o=.C>UXkbVGTrr~>
endstream
endobj
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