This term should denote half of the peak-to-peak amplitude. Peak-to-peak and r.m.s. amplitudes should be so specified.
Source:
PAC, 1985, 57, 1491. 'Recommended terms, symbols, and definitions for electroanalytical chemistry (Recommendations 1985)' on page 1505 (https://doi.org/10.1351/pac198557101491)