Hi,
 
During my work on bachelor thesis I was running throught source codes and I would like to ask about equivalent of file syst-gen.mkii in MkIV. And if there isn't one. Where I can found definitions of macros define in this file (like \dosingleargument and so on).
 
Also I have another question. In file page-lay.mkii there is definition:
 
\def\addpagecutmarks % #1
  {\executeifdefined{\??ly:n:\c!marking:\@@lymarking}\gobbleoneargument}
 
I don't understand this part: {\??ly:n:\c!marking:\@@lymarking}, especially I don't know what ":n:" does or means. Can someone briefly explain it to me?
 
Thanks for your help.
 
Tomas Pustelnik