.xx "intro" "Miscellaneous useful information pages" .xx "ascii" "map of ASCII character set" .xx "environ" "user environment" .xx "eqnchar" "special character definitions for eqn" .xx "hier" "file system hierarchy" .xx "man" "macros to typeset manual" .xx "me" "macros for formatting papers" .xx "ms" "macros for formatting manuscripts" .xx "term" "conventional names"