Recently, this question was put on hold: Why is "their" italicized?
I'm wondering, why it is considered out of scope? If it's considered to be too close to "analysis of literature," that would seem to me like a valid reason in principle, although I might disagree. However, in the comments section, Oldcat suggested that the reason the question was off-topic was because
Italics are for emphasis, and are not part of the English language.
I don't think this is a valid reason to close a question, and as Mortimer Ballsack pointed out, there are already many questions on the site tagged with italics. Should they all be closed?
In the Help Center, it is stated that questions about "Spelling and punctuation" are on topic. Italics are not exactly either, but I feel they are similar. I understand that this is "English Language and Usage" Stack Exchange, not Typography Stack Exchange, but there are elements that overlap. I think questions about the use of typographical elements in English, such as ligatures or italics, should be considered on topic (assuming the question is not about graphic design.)
There can be differences between languages in the use of italics; see this article about German punctuation for some examples of where German writers use quotation marks where an English writer would use italics.