¹ Butrica's choice of sigla is illogical. One might reasonably use Roman capitals for authoritative MSS, Greek capitals for lost hyparchetypes, and Greek minuscules for groups providing humanistic conjectures. But if P, an interpolated descendant of A, is to remain P, why should the new group, independent throughout the text, be given lower case sigla? And it can only confuse readers of the apparatus if a is used for the agreement of FLPZ, independent witnesses in the absence of A, whilst M is used for a lost manuscript of no authority which is cited for its conjectures. I shall, however, use Butrica's sigla here, merely adding Π for Petrarch's manuscript.