Finally, someone actually® uses an asterisk as it's *supposed.

I've never quite figured out what this board's unique usage of the asterisk is. I've seen it used in olden times gone by as a marker of footnotes; in linguistics it first marked hypothetical reconstructions and second ungrammatical sentences; after finding onlinehood asterisks delimited some sort of emphasis. But now here I see a single asterisk, prepended to a word, and I gotta wonder. Is there a locus classicus for this usage?