Most readers know that superscript figures (usually numbers or asterisks) in text tell the reader to refer to a footnote or an endnote for a comment or a source reference. So informative writers of white papers and such will want to use superscript characters here and there to build up their credibility.
As always, proper punctuation is critical to that effort. But if a superscript figure is at the end of the sentence, where exactly does it go? Inside or outside the closing punctuation? And is there any space before the superscript figure?
Answer: Do not leave any space between the superscript figure and the preceding word. If a punctuation mark follows the word, place the superscript figure immediately after the punctuation mark.
Source: The Gregg Reference Manual