tracking – Adjust tracking of strings

Au­to­mat­i­cally ad­just spaces be­tween sym­bols in words or phrases to fit them into a spec­i­fied length. Any chain of sym­bols (in­clud­ing spaces) in the cur­rent font may be treated.
Com­mands \track{}{} (add space , which may be <0, after each symbol of ), \fit­track{}{} (make fit into width , which may be smaller than the orig­i­nal width) and \ra­tio­track{}{} (as \fit­track, with re­placed by of the nat­u­ral length of ).