Dear gang,

I made a wiki page for \feature et al:

http://wiki.contextgarden.net/Open_Type_Fonts_and_Featuresets_in_MkIV

Towards the end we need a graphical sample of the sample file, but I do  
not know how to do that. See

=======
Now let us review the results:

[output/graphic here]
=======

I have to move on to other projects so I'm leaving completion and  
improvement to others in the community. Here is the sample file (needs  
latest beta! pdf attached as well) that needs graphical output on the page:

==============
\definefontfeature
   [schola-preset]
   [mode=node,script=latn,language=dflt,kern=yes,liga=yes,lnum=yes]

  \starttypescript [serif] [schola-preset] [name]
  \definefontsynonym [Serif]  
[name:texgyreschola-regular.otf][features=schola-preset]
  \stoptypescript

  \starttypescript [serif] [schola-preset] [size]
     \definebodyfont
      [35.8pt,29.8pt,24.8pt,20.7pt,17.3pt,14.4pt,12pt,11pt,10pt,9pt,8pt]
      [rm]
      [tf=Serif sa 1]
  \stoptypescript

  \starttypescript [schola-default]
  \definebodyfontenvironment
   [schola-default]
   [default]
   [interlinespace=2.7ex]
\definetypeface [schola-default] [rm] [serif] [schola-preset]  
[schola-preset] % [default]
  \stoptypescript

  \usetypescript[schola-default]
  \setupbodyfont[schola-default,12pt]

\definefontfeature[f:smallcaps]   		[smcp=yes]
\definefontfeature[f:thinimacron] 		[ss04=yes]
\definefontfeature[f:upsidedown] 		[dlig=yes]


\definefontfeature[f:newstyle]			[onum=no]
\definefontfeature[f:nocaps]       		[smcp=no]
\definefontfeature[f:wideimacron]  		[ss04=no]
\definefontfeature[f:rightsideup] 		[dlig=no]


\definefontfeature[f:ligatures] 		[liga=yes]
\definefontfeature[f:noligatures] 		[liga=no]

\definefontfeature[f:oldstyle]			[onum=yes,lnum=no]

\definefontfeature[f:oldstyleupsidedown]	[onum=yes,dlig=yes]
\definefontfeature[f:newstylerightsideup]	[onum=no,dlig=no]

\definefontfeature[f:oldstylewmacron]	[ss04=no,onum=yes]
\definefontfeature[f:newstylesmallcaps]	[smcp=yes,onum=no]

\startTEXpage[offset=10pt]

\define\SAMPLE{123 Idrīs ?` !` VA fi}

\SAMPLE\blank

\feature[+][f:oldstyle] 		\SAMPLE \blank
\feature[more][f:thinimacron] 	\SAMPLE \blank
\addfeature[f:upsidedown] 		\SAMPLE \blank

\feature[+][f:smallcaps] 		\SAMPLE \blank
\addfeature[f:wideimacron] 		\SAMPLE \blank

\feature[-][f:upsidedown] 		\SAMPLE \blank

\feature[=][f:oldstyleupsidedown]\SAMPLE \blank

\feature[!][f:smallcaps]		\SAMPLE \blank

\feature[<]				\SAMPLE \blank
\stopTEXpage
==============

Thanks and best wishes
Idris
-- 
Professor Idris Samawi Hamid
Department of Philosophy
Colorado State University
Fort Collins, CO 80523