sub­script – Pro­vides the \textsub­script com­mand

Pro­vides a com­mand \textsub­script, which is a mod­i­fied ver­sion the com­mand \textsu­per­script that's part of LaTeX. The com­mand is also (now) pro­vided by the fixltx2e pack­age dis­tributed with LaTeX it­self; if you are run­ning a LaTeX dis­tri­bu­tion no ear­lier than 2005/12/01, you will have a more sat­is­fac­tory means of us­ing the com­mand.
Sub­script is one of a se­ries of frag­ments de­signed for use by pack­age writ­ers and oth­ers.