I tested Most of cases and TRTH returns Price RIC .
Here the list used to query .
ISN,FR0126461682,,MTFISN,BE0312774467,,MTBISN,BE0312773451,,MTBISN,FR0126461682,,MTFISN,FR0126310301,,MTFISN,FR0126461658,,MTFISN,BE0312775472,,MTBISN,FR0125848475,,MTFISN,FR0126310277,,MTFISN,BE0312776488,,MTBISN,FR0126461609,,MTFISN,FR0126310293,,MTFISN,FR0126310285,,MTFISN,FR0126310269,,MTFISN,BE0312779516,,MTBISN,FR0126461690,,MTFISN,BE0312778500,,MTBISN,NL0014926388,,MTS
All the Bonds in the list are Zero coupn bons and traded in Yield on specified exchanges.
Thanks