General Rules:
* Punctuation after superscripts/subscripts: This is the most common approach, especially in scientific and technical writing. It ensures that the punctuation applies to the entire expression, not just the superscript or subscript.
* Punctuation before superscripts/subscripts: This approach can be used in some contexts, such as when the superscript or subscript is a footnote marker or a reference.
Style Guide Examples:
* Chicago Manual of Style: Generally advocates for placing punctuation *after* superscripts and subscripts, except for footnote markers (which go *before*).
* American Psychological Association (APA) Style: Recommends placing punctuation *after* superscripts and subscripts.
* MLA Style: While MLA doesn't explicitly address superscripts/subscripts, it aligns with the general principle of placing punctuation after them for clarity.
Examples:
* After: "This is a sample sentence with a superscript, H2O2.¹"
* Before: "This is a sample sentence with a superscript.¹" (For footnotes)
Important Considerations:
* Context: The specific context and purpose of your writing will influence the best choice.
* Clarity: Choose the option that makes your writing the most clear and understandable to your audience.
Overall: While there are general principles, the best practice is to follow the specific style guide relevant to your writing. If no style guide is specified, placing punctuation after superscripts and subscripts is generally the most reliable option.