Protein/polypeptide nomenclature, residue number superscripted or not?

When referring to a specific residue number of a given amino acid, should the residue number be superscripted or simply affixed?


For example, When referring to a Tryptophan residue at the 147th position, which is the best notation?



> 
> $Trp^{147}$ vs Trp147 vs Trp-147
> 
> 
> 


I can't seem to find any guidelines that strictly prohibit the superscript notation, and I think aesthetically it's easier to read, but it seems less common and perhaps incorrect.


It seems to me that `Trp147` is the preferred notation, while the superscript version is reserved to indicate derivatives, such as replacements and deletions, but not expressly prohibited; `Trp-147` is discouraged, I believe. It also seems that superscripts are used in special circumstances, to denote all sorts of things ([for example: GCPRs](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4408928/)[GCN numbering](https://www.mrc-lmb.cam.ac.uk/CGN/about.html)), so perhaps this is why superscripts aren't used for ordinary residues.


So, is there any consensus on this? Is it a hard rule or more of a stylistic preference?


Ref: <https://iupac.qmul.ac.uk/AminoAcid/AA22.html>


I've seen `Trp147` notation quite commonly, but I've also seen the superscript version used for ordinary notation of typical protein residues.


Example of `Trp147` notation style:
<https://www.nature.com/articles/nature07938>


Example of superscript ($Trp^{147}$) notation style: <https://www.sciencedirect.com/science/article/pii/S002192581894785X>


