Full Idea
The valid formulas of classical sentential logic are called 'tautologically valid', or simply 'tautologies'; with other logics 'tautologies' are formulas that are substitution instances of valid formulas of classical sentential logic.
Gist of Idea
'Tautologies' are valid formulas of classical sentential logic - or substitution instances in other logics
Source
John P. Burgess (Philosophical Logic [2009], 1.5)
Book Reference
Burgess,John P.: 'Philosophical Logic' [Princeton 2009], p.6