Notes. Columns 1 and 2 give the source name and its distance. Almost all distance estimates are based on trigonometric parallax measurements except for RCW49 where the distance is based on photometric estimates. Column 3 is the mass determined from Herschel dust column density, most of the values are reported in Schneider et al. (2022). Column 4 is the equivalent radius ${\text{r}}_{cloud}=\sqrt{A/\pi }$, given by the area A of the cloud. The area is defined by the A_v = 1 contour (Schneider et al. 2022) or taken from the literature for M42 and S106. Column 5 lists the O-star content of the region, partly taken from Schneider et al. (2020), and updated literature values. Column 6 specifies the estimated age of the cluster. Column 7 is the line centre velocity of the molecular cloud, determined from a Gaussian fit to the ¹³CO line. Columns 8 and 9 specify the blue (b) and red (r) range of high-velocity emission. Column 10 gives the escape velocity. (1) Menten et al. (2007), (2) Stoop et al. (2023), (3) Wu et al. (2019), (4) Kuhn et al. (2019), (5) Bonne et al. (2023b), (6) Zucker et al. (2020), (7) Moscadelli et al. (2009), (8) Zeidler et al. (2015), (9) Comerón et al. (2022), (10) Xu et al. (2013), (11) Da Rio et al. (2010), (12) Hanson et al. (1997), (13) Martins et al. (2010), (14) Ellerbroek et al. (2013), (15) Puga et al. (2010), (16) Comerón et al. (2018).⁺ If known, the spectral type of the O-star is given. WR signifies Wolf–Rayet star. (*) The mass is an upper limit from Schneider et al. (2022), values in the literature are 3.2 × 10⁵ M_⊙ from dust (Dupac et al. 2002) and range, based on CO observations, from 1.35 × 10⁵ M_⊙ (Povich et al. 2009) to 2.8 × 10⁵ M_⊙ (Elmegreen et al. 1979) (**) The results for RCW120 and RCW79 rely solely on age estimates of the ionizing stars, not on cluster-member ages. (***) The age estimate of the central O9 star of S106 is not well constrained.