There is the old non-Unicode method where the PDF file is created via a non-Unicode device type. In this case, the PDF must be created by a SAPscript form or Smart Form with the correct language key and the fonts need to to support the language characters. The device type used must be a suitable device type for the required language.
In Unicode systems only, the Unicode PDF conversion method is possible. The PDF in this case must be created via a cascading fonts Unicode device type like SWINCF or PDFUC.
Non Unicode Method
The first method is the old non-Unicode method where the PDF file is created via non-Unicode device types like SAPWIN, CNSAPWIN, I2HP4, I7SPOST etc. In this case, the PDF must be created by a SAPscript form or a Smart Form with the correct language key and the fonts used in the Smartform need to to support the language characters. Also the device type used must be a suitable device type that supports the required language.
An example of this is if you want to create a PDF for a form that uses Russian(Cyrillic) characters. The form must have a language key RU. The SAP fonts used in the form must be Russian fonts like COURCYR, TIMECYR and HELVCYR. True type fonts that support Russian characters must be uploaded into the SAP system under font families COURCYR, TIMECYR and HELVCYR via report RSTXPDF2. Finally a device type that supports Cyrillic characters like SAPWIN or SAPWIN5 must be used to create the PDF data. This information applies for Unicode systems also if you use a non-Unicode device type.
Unicode Method for PDF Conversion
In Unicode systems only, the Unicode PDF conversion method is possible. The PDF in this case must be create via Unicode device types like SWINCF or PDFUC. With this method, the language key of the form is no longer important. The characters are mapped to a suitable font based on the Unicode range that they belong to. For languages which have characters that are not supported by Adobe's internal fonts, it is again necessary to upload true type fonts to the SAP system. For the Unicode PDF conversion method via PDFUC or SWINCF, the fonts should be uploaded via report RSTPDF2UC.There is more information about this topic in SAP Note 999712 and the PDF_Font_Installation_Guide document contained in the note attachments.
Fonts for CJK Asian languages
For both methods above, when creating PDFs with CJK Asian languages, no true type fonts are needed. The internal Adobe fonts support these languages. Also, any true type font that supports all the characters for these languages is much too large to embed into a PDF file.
Application Interface for PDF Creation with Forms
For PDF conversion of SAPscript forms and Smart Forms, this can be done by the application that creates the OTF spool data and then a function module like CONVERT_OTF being used to create the PDF data from the OTF data. In this case, it is the device type, form language key and fonts used to create the OTF data that is important.
It is also possible to call the Sapscript function module OPEN_FORM with parameter DEVICE=MAIL. In this case the PDF conversion is done via SAPCONNECT. It is similar if the application calls the Smartform function module with the parameter CONTROL_PARAMETERS-DEVICE = 'MAIL'.
When the PDF is created via SAPCONNECT, for the device type used, it is the setting in SAPCONNECT(transaction SCOT) that is important.
SCOT → Settings → Device Types for Format Conversion
Here device types can be maintained for the various languages and it is this device type that is used to create the PDF file. It is important that the device type supports the language specified.