+& thing thing... & => each thing prefixed by &/ &^ &~ resp
+& ^ thing thing... & each thing is any non-ws
+& ~ thing thing... & & may be omitted before EOL or before \EOL
+ other &'s not recognised
+
+CAPS is [A-Z][0-9_A-Z]*(?!\w)
+lc is [a-z][-+,0-9_a-z]*(?!\w)
+
+&!<spaces or tabs> disables & *until* EOL (and disappears)