Substructure abbreviations with the SMILES format

I am trying to use the SMILES format for encoding molecules from handwritten logbooks. The molecules often contain abbreviations, such as "Ph" for a Phenyl group. Is there a way to have these abbreviated structures in SMILES?




So far, I didn't encounter an equivalent of `Ph` in the world of SMILES.


Though SMILES (and SMARTS) represent chemical structures (and reactions) in a reduced, simplified form, I would recommend to stick to clearly sketched structural formulae to keep the content of the (handwritten) logbook easy accessible for your colleagues;\* especially for those joining the group/enterprise after your left the organization (the *reading* of the information stored). For one, the strings can become lengthy and complex (see e.g. the documentation compiled by Daylight, [part theory](https://daylight.com/dayhtml/doc/theory/theory.smiles.html) and [part tutorial](https://daylight.com/dayhtml_tutorials/languages/smiles/index.html)) and you may be faster to (manually) doodle the structure, than composing the string.


For two, if you turn to programs like [openbabel](https://github.com/openbabel/openbabel) to work with them and other (chemistry relevant) file formats, you will meet multiple SMILES dialects out there. Staying with said program openbabel for example, it can report SMILES in their canonical, or universal, or in their InChI-fied form ([ref. documentation](https://open-babel.readthedocs.io/en/latest/FileFormats/SMILES_format.html)). Especially with the structural more complex molecules, the output as a string *can* differ; even more likely if SMILES are assigned to a structure by different programs (e.g., GUI based [chemdraw](https://chemdrawdirect.perkinelmer.cloud/js/sample/index.html), or programming libraries like [RDKit](http://rdkit.org/). Already benzene can be expressed (at least) by either `c1ccccc1` with implicit aromaticity, or `c:1:c:c:c:c:c1`, or with Kekulé SMILES `C1=CC=CC=C1`; each of these forms has its pros and cons (e.g. explicit electron count/localization).


\* Don't forget outside chemistry and personal trained in STEM only, a lab's log equally may become relevant e.g. for a patent attorney, too.


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