ive marked fowl for yrs by using the toe web method. im not a fan of punching. the punches can grow shut, or will tear out. i prefer the notching method, you just take a pair of cuticle scissors and cut the web out between the toes. you can use the chart in the link given but substitue the punches with notches....or some will incorporate the punches and notches together to give you a hundred more options of marking.
you can buy toe punches at many online poultry supply stores.