Maximum-transcendentality conjecture for loop amplitudes

Consider an $L$-loop amplitude in dimensional regularisation with $D=4-2\epsilon$, and write its Laurent expansion in $\epsilon$. Maximum-transcendentality conjecture. The Laurent coefficient of $\epsilon^k$ contains terms of weight at most $2L+k$. The source notes that only a few theorems establish such weight bounds for specific classes of loop integrals, so the generic statement remains conjectural.