Table 5: Summary of the spectral and photometric properties of the well studied objects as discussed in Sect. 4. Column 1: object name; Col. 2: spectral type; Cols. 3-6: spectral features detected in their K-band spectra; Cols. 7 (J - K) value, dereddened for foreground extinction; Col. 8: absolute, dereddened K-band magnitude; Col. 9: references: G87: Geballe & Persson (1987), C89: Carr (1989), C93: Chandler et al. (1993), C95: Chandler et al. (1995), vdA00: van den Ancker et al. (2000), S83: Scoville et al. (1983), L04: Lenorzer et al. (2004), vdA04: E02: Eiroa et al. (2002), van der Ancker (2004), C00: Clark & Steele (2000), D94: Dougherty et al. (1994), M88: McGregor et al. (1988), M96: Morris et al. (1996), V99: Voors (1999). : These values are for the B[e] supergaints.

Object/	Sp. Type	Br	Pf	HeI	CO	MgII/FeII	E(J - K)	K	References
Object type
S106	O6-O8 V	+	+	-	+	-	0.6	-5.4	G87, C89, C93, C95, vdA00
BN	B0.5V	+	-	-	+	+	-	-	S83, G87, C89
NGC 2024-IRS2	B0V	+	+	-	+	+	0.9	-7.0	G87, C93, C95, L04
Herbig Ae	F - late B	+	-	-	-	-	1.5	2 - -2	E02, vdA04
Herbig Be	B	+	?	+	some	-	2-6	-1--5	E02, vdA04
Be	B	+	+	some	-	some	0.0-0.6	0--3	D94, C00
B[e]	B	+	+	some	+	+	2-6	-6--10	M88,M96,V99