Notes. Columns: (1) Modified Julian Date (Universal Time) of observations, (2) phase with respect to observed maximum light, (3) telescope and instrument used for polarimetry observations, (4) grism or filter used, (5) exposure time per HWP angle (corresponding to the respective filter bands in column (4) in case of broadband polarimetry), (6) photometry used to scale the flux spectrum and host spectra to perform the host correction, and (7) telescope and instrument used to obtain the transient and host spectra, along with the observation date. For the spectropolarimetric observations, only the host spectrum is given. The referenced spectra of AT 2018hyz were already scaled and host-subtracted by Short et al. (2020), Gomez et al. (2020). In the case of AT 2022exr, the phase corresponds to the first peak in its light curve.