The paper discusses the coevolution of supermassive black holes (BHs) and their host galaxies, focusing on methods to estimate BH masses. It presents a supplement to the main paper, covering BH mass measurements, classification criteria for bulges, and corrections to galaxy and BH parameters. The supplement includes detailed discussions on reverberation mapping, single-epoch spectroscopy, and the X-ray–radio–M "fundamental plane" method for estimating BH masses. It also addresses the classification of classical and pseudo bulges, emphasizing the importance of distinguishing between them for accurate BH mass estimates. The supplement provides corrections to parameters such as 2MASS apparent magnitudes, effective velocity dispersions, and BH masses, ensuring more accurate results. The paper highlights the challenges in measuring BH masses, particularly for distant galaxies where spatial resolution is limited. It also discusses the impact of different BH mass estimation methods on the interpretation of BH-host coevolution. The supplement includes detailed corrections for galaxy magnitudes, effective velocity dispersions, and BH masses, ensuring consistency with other measurements. The paper concludes that while BH mass estimates are generally reliable, there are still uncertainties, particularly for low-mass BHs and for galaxies with unusual properties. The results are summarized in tables, and the paper emphasizes the importance of accurate BH mass measurements for understanding the coevolution of BHs and their host galaxies.The paper discusses the coevolution of supermassive black holes (BHs) and their host galaxies, focusing on methods to estimate BH masses. It presents a supplement to the main paper, covering BH mass measurements, classification criteria for bulges, and corrections to galaxy and BH parameters. The supplement includes detailed discussions on reverberation mapping, single-epoch spectroscopy, and the X-ray–radio–M "fundamental plane" method for estimating BH masses. It also addresses the classification of classical and pseudo bulges, emphasizing the importance of distinguishing between them for accurate BH mass estimates. The supplement provides corrections to parameters such as 2MASS apparent magnitudes, effective velocity dispersions, and BH masses, ensuring more accurate results. The paper highlights the challenges in measuring BH masses, particularly for distant galaxies where spatial resolution is limited. It also discusses the impact of different BH mass estimation methods on the interpretation of BH-host coevolution. The supplement includes detailed corrections for galaxy magnitudes, effective velocity dispersions, and BH masses, ensuring consistency with other measurements. The paper concludes that while BH mass estimates are generally reliable, there are still uncertainties, particularly for low-mass BHs and for galaxies with unusual properties. The results are summarized in tables, and the paper emphasizes the importance of accurate BH mass measurements for understanding the coevolution of BHs and their host galaxies.