An acronym in cheminformatics: AAA for atom-anchored annotation

Triple A: in cheminformatics this letter repetition stands for atom-anchored annotation (AAA). An AAA is an attribute (color) of a node in the hydrogen-suppressed molecular graph. In a CurlySMILES notation, such nodes are encoded as ANCs (SQCs, in particular) and can be followed by one or more AAAs to specify atomic or molecular details or to modify the molecular graph representation. The following AAA types are defined in CurlySMILES:

• stereodescriptive annotation,
• structural unit annotation,
• group environment annotation,
• molecular detail annotation, and
• operational annotation.
  

The open format of the CurlySMILES language allows the addition of further, novel categories. Suggestions are always welcome!

References
[1] Axel Drefahl: CurlySMILES: a chemical language to customize and annotate encodings of molecular and nanodevice structures. Journal of Cheminformatics 2011, 3:1.
DOI: 10.1186/1758-2946-3-1.
[2] Axel Drefahl: The CurlySMILES Project [www.axeleratio.com/csm/proj/main.htm].