Full Idea
A theory of truth is 'reflexive' if it allows us to prove truth-iterations ("It is true that it is true that so-and-so").
Gist of Idea
'Reflexive' truth theories allow iterations (it is T that it is T that p)
Source
Leon Horsten (The Tarskian Turn [2011], 01.4)
Book Reference
Horsten,Leon: 'The Tarskian Turn' [MIT 2011], p.8