A batch of spectra are removed from DR7 because of a mix-up between low and medium resolution spectra in some days. Details are described as follows:
(1) We remove 6404 spectra from the low-resolution part of DR7. These spectra are from 4 plates observed on March 25, 2018, which are HIP368380101, HIP450460101, HIP61358C1001 and HIP8007401 respectively.
(2) For the medium-resolution part of DR7, we remove 127820 spectra from the single-exposure data, and 37416 spectra from the combined spectra. These spectra are observed by spectrograph number 1 in 21 observation days which are from December 3, 2017 to February 3, 2018.