-There are three types of escape sequences: header
-.IR components ,
-built-in
-.IR functions ,
-and flow
-.IR control .
-Comments may be inserted in most places where a function argument is
-not expected. A comment begins with `%;' and ends with a (non-escaped)
+There are four types of escape sequences:
+.PP
+.RS 5
+.nf
+.ta +\w'name of escape class xxxxxxx'u
+.RI "1) header components %{" component }
+.RI "2) built-in functions %(" "function arg" )
+.RI "3) flow control %< ... %? ... %| ... %>
+.RI "4) comments %; ...
+.fi
+.RE
+.PP
+Comments may be inserted in most places where no function argument is
+expected. A comment begins with `%;' and ends with a (non-escaped)