Analysis of information sources in references of the Wikipedia article "Vernier thruster" in English language version.
The flight crew can select primary or vernier RCS thrusters for attitude control in orbit. Normally, the vernier thrusters are selected for on-orbit attitude hold. ... The forward RCS had 14 primaries and two vernier engines. The aft RCS had 12 primary and two vernier engines in each pod. The primary RCS engines provided 870 pounds of vacuum thrust each, and the verniers provided 24 pounds of vacuum thrust each. The oxidizer-to-fuel ratio for each engine is 1.6-to-1. The nominal chamber pressure of the primary thrusters was 152 psia. For each vernier, it was 110 psi.