\def\one{simple}% \def\two#1{argument(#1)}% \def\three#1=#2{arguments(#1<>#2)}% \def\four#1#2#3{reverse(#3(#2)#1)}% % this is simple: \one. this is argument: \two{hello}. this is arguments: \three A=B. this is reverse: \four{foo}{bar}{baz}. % \def\swap#1#2{#2#1}% \def\bracket#1{[#1]}% % this is swapped bracket: \swap\bracket{A}{B}. this is swapped bracket: \bracket\swap{A}{B}. Comment the end of this % line out. But no comment the end of this \% line.