YSCC visual extinction and total infrared luminosity as a function of FUV luminosity. In the lower and upper left panels we show sources associated with GMCs, in the lower and upper right panel we show sources not associated with GMCs. Blue circles: embedded b-type sources; red squares: YSCCs of c1-type; green stars: YSCCs of c2-type; cyan filled triangles: unclassifiable sources with GMCs; magenta triangles: YSCCs without GMCs; and black crosses: sources of unknown nature without GMCs (e-type). Continuous lines of unity slope in all four panels are not fits to the data, but are drawn for reference.