... stars[*]
Based on observations collected at the European Southern Observatory, Paranal, Chile (program numbers 071.C-0653, 072.C-0648, 073.C-0245 and 074.C-0248). 
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...[*]
Figure 1, Table 4 and Appendix A are only available in electronic form at http://www.edpsciences.org 
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...B. Acke1,[*]
Postdoctoral researcher of the Research Fund KULeuven. 
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... ISAAC[*]
http://www.eso.org/instruments/isaac/ 
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... lacking[*]
No STD in the 3.3 $\mu $m region on 04-05/09/2003 and 06-07/ 10/2004; no STD in both the 3.3 and 3.5 $\mu $m regions on 18-19/11/2003 and 17-18/07/2004; no calibration files on 04-05/11/2003 and 20-21/10/2004. 
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... TIMMI2[*]
http://www.ls.eso.org/lasilla/sciops/3p6/timmi/ 
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... sources[*]
We have classified T CrA as group II member and V921 Sco as embedded source in stead of in group I (as was done by AV04). 
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... present[*]
Except for HD 142527, a PAH 3.3 $\mu $m detection which was however not confirmed by the ISAAC spectrum. 
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... theorem[*]
$P(B) = \frac{P(B\vert A)~\cdot~P(A)}{P(A\vert B)}$ with A and B stochastic events. In this case A and B represent the detection of the 3.3 and the 6.2 $\mu $m feature in the spectrum, respectively. 
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Copyright ESO 2006