A question for Chemistry Collection users: are you interested in support for enhanced stereo in SMILES format? Larger sets of extensions exist, but a simple implementation could follow the terminology of CTABs by using "Abs", "And", and "Or" labels for individual atoms:

C[C@[Or2]H]1CCC[C@[And2]H]([C@[Or2]H]1C)C2=N[C@[Abs]H](C)C(=O)Nc3cc(ccc23)[C@[And1]H]4CCC[C@[Or1]H](O)[C@@[Or1]H]4O (See image "Mixed Stereo.png")

and use the presence or absence of "And" labels to mimic the Chiral flag:

N[C@@H](Cc1c[nH]c2ccccc12)C(=O)O vs. N[C@@[And]H](Cc1c[nH]c2ccccc12)C(=O)O (See image "Chiral Flag.png")

Or we could implement the Enhanced Stereo Representation of CXSMILES (the "a", "o", and "&" tags). We’re interested in feedback about the level of interest and potential use cases.