Changes

Arthur has been kind enought enough to provide a few links to official documents from Adobe and Microsoft that explain everything in great detail: [* [http://www.microsoft.com/typography/otspec/GSUBgsub.htm 1]] and [The page of the OpenType specification that explains the use of GSUB* [http://www.adobe.com/devnet/opentype/afdko/ topic_feature_file_syntax.html 2]The page of the Adobe Font Development Kit documentation that describes fea files.* [http://fontforge.sourceforge.net/featurefile.html 3]. The page from the FontForge manual that describes various extensions to the Adobe syntax that are in use by luatex Good luck with your own experiments!