PDF:
http://www.adobe.com/devnet/pdf/pdf_reference_archive.html
Postscript AFM/PFA/PFB:
http://www.adobe.com/content/dam/Adobe/en/devnet/font/pdfs/5004.AFM_Spec.pdf http://www.adobe.com/content/dam/Adobe/en/devnet/font/pdfs/5040.Download_Fonts.pdf
TrueType/OpenType:
http://www.microsoft.com/typography/otspec/otff.htm http://www.microsoft.com/typography/otspec/TTOREG.htm https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6.html
CFF:
http://www.adobe.com/content/dam/Adobe/en/devnet/font/pdfs/5176.CFF.pdf
JPEG:
http://www.w3.org/Graphics/JPEG/
PNG:
http://www.w3.org/TR/PNG/
Diskussion