For a composition I whose last part exceeds 1, we can define the multiple t-value t(I) as the sum of all the terms in the series for the multiple zeta value \(\zeta (I)\) whose denominators are odd. In this paper we show that if I is composition of \(n\ge 3,\) then \(t(I)=(-1)^{n-1}t({{\bar{I}}})\) mod products, where \({{\bar{I}}}\) is the reverse of I, and both sides are suitably regularized when I starts or ends in 1. This result is not true for multiple zeta values, though there is an argument-reversal result that does hold for them (and for multiple t-values as well). We actually prove a more general version of this result, and then use it to establish explicit formulas for several classes of multiple t-values and interpolated multiple t-values.
