Phase abbreviations for non-aqueous solutions

Question

When writing a chemical equation, how do you indicate that a chemical is dissolved in a non-aqueous solvent?

For example, it would be inappropriate to write

X (aq)

when X is dissolved in benzene, since aq stands for "aqueous," implying water soluble. A previous answer provided the potential abbreviation (sol), but I wonder if that is actually correct/commonly used.

How would you indicate that X is dissolved in a non-aqueous solvent?

Answer 1

According to IUPAC, general notation for any solution would be $\ce{X(sln)}$ [1, p. 54]:

(vi) States of aggregation

The following one-, two- or three-letter symbols are used to represent the states of aggregation of chemical species [...] The letters are appended to the formula symbol in parentheses, and should be printed in Roman (upright) type without a full stop (period).

$$ \begin{array}{ll} &\ldots\\ &\text{s} &\text{solid}\\ &\text{sln} &\text{solution}\\ &\text{vit} &\text{vitreous substance}\\ &\ldots\\ \end{array} $$

Similarly, when denoting relation of a given quantity/symbol, subscript $\mathrm{sln}$ notation is used, e.g. $Δ_\mathrm{sln}G^\circ(T,p^\circ)$ [2, pp. 241, 276]:

4.2 Subscripts and superscripts

4.2.1 Subscripts

$$ \begin{array}{ll} &\ldots\\ &\text{r} &\text{reference, reduced}\\ &\text{sln} &\text{solution}\\ &\text{s} &\text{saline solution}\\ &\ldots\\ \end{array} $$

References

1. IUPAC “Green Book” Quantities, Units, and Symbols in Physical Chemistry, 3rd ed.; Cohen, R. E., Mills, I., Eds.; IUPAC Recommendations; RSC Pub: Cambridge, UK, 2007. ISBN 978-0-85404-433-7.
2. Gamsjäger, H.; Lorimer, J. W.; Scharlin, P.; Shaw, D. G. Glossary of Terms Related to Solubility (IUPAC Recommendations 2008). Pure and Applied Chemistry 2008, 80 (2), 233–276. https://doi.org/10.1351/pac200880020233.