OB version: 2.1.1
Converting the attached SDF file to SMILES produces the following output:
$ babel -isdf DB03043.sdf -osmi
NC(Cc1c[nH]c2[se]ccc12)C(O)=O SDF file of DB03043
1 molecule converted
13 audit log messages
Which in a strict sense is wrong according to the openSMILES specification as non-aromatic atoms start with uppercase characters.
SDF file used to generate the output.
Logged In: YES
user_id=1189615
Originator: NO
The sdf file has the selenium as part of an aromatic structure (its bonds are aromatic). There is no ambiguity in the SMILES structure; it is understood by Daylight's Depict, MarvinView and OpenBabel, although not Chem Sketch. OpenSMILES is not yet finallized and this issue is contentious. I think it is not appropriate to make changes to OpenBabel's output at the moment but just to note it as a possible bug for the future. I have reduced the priority.
Chris