Notes. Previously known clusters can be found in the catalogues indicated. Confirmations from follow-up do not include the observations performed by the Planck collaboration to measure missing redshifts of known clusters. Confirmation from archival data covers X-ray data from Chandra, XMM, and ROSAT PSPC pointed observations only. References to individual source catalogues mentioned in this Table can be found in Planck Collaboration XXIX (2014). In a number of cases, NED and SIMBAD were used to obtain supporting information such as redshifts, and the original references are listed in Planck Collaboration XXIX (2014).