Does anyone know if the Coupe had a factory project number starting with "X1/...."

Obviously Fiat used the X1/9's project number as its final name and I know the 128 was the X1/1, the Autobianchi A112 was the X1/2, the Fiat 130 was the X1/3, the 127 was the X1/4, the Lancia Montecarlo was firstly the X1/8 then the X1/20 and the Ritmo was the X1/38... so did the Coupe have one?