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4.4 8-Bit Encodings8-bit encodings (also called single-byte encodings) map each byte in a text string to asingle character, and are thus limited to 256 different characters at a time.Table 4.4 lists the predefined encodings in PDFlib, and details their use with severalimportant classes of fonts. It is important to realize that certain scripts or languageshave requirements which cannot be met by common fonts. For example, Acrobat’s corefonts do not contain all characters required for ISO 8859-2 (e.g. Polish), while PostScript3, OpenType Pro, and TrueType »big fonts« do.Note The »chartab« example contained in the PDFlib distribution can be used to easily print charactertables for arbitrary font/encoding combinations.Notes on the macroman encoding. This encoding reflects the Mac OS character set, albeitwith the old currency symbol at position 219 = 0xDB, and not the Euro glyph as redefinedby Apple (this incompatibility is dictated by the PDF specification). The macroman_appleencoding is identical to macroman except for the following differences:> Position 219 = 0xDB in macroman_apple holds the Euro glyph instead of the currencysymbol.> The macroman_apple encoding includes the greek/mathematical symbols as definedin the Mac OS character set. Although these are available in the macroman_apple encoding,the required glyphs are contained only in few fonts.Host encoding. The special encoding host does not have any fixed meaning, but will bemapped to another 8-bit encoding depending on the current platform as follows:> on Mac OS Classic it will be mapped to macroman;> on IBM eServer zSeries with MVS or USS it will be mapped to ebcdic;> on IBM eServer iSeries it will be mapped to ebcdic_37;> on Windows it will be mapped to winansi;> on all other systems (including Mac OS X) it will be mapped to iso8859-1;Host encoding is primarily useful for writing platform-independent test programs (likethose contained in the PDFlib distribution) and other simple applications. Host encodingis not recommended for production use, but should be replaced by whatever encodingis appropriate.Encoding host is used as the default encoding for Name strings in non-Unicodeawarelanguage bindings, since this is the most appropriate encoding for file names etc.Automatic encoding. PDFlib supports a mechanism which can be used to specify themost natural encoding for certain environments without further ado. Supplying thekeyword auto as an encoding name specifies a platform- and environment-specific 8-bitencoding for text fonts as follows:> On Windows: the current system code page (see below for details)> On Unix and Mac OS X: iso8859-1 (except LWFN PostScript fonts on the Mac for whichauto will be mapped to macroman)> On Mac OS Classic: macroman> On IBM eServer iSeries: the current job’s encoding (IBMCCSID000000000000)> On IBM eServer zSeries: ebcdic (=code page 1047).4.4 8-Bit Encodings 81