French law often adds a “bis” (e.g. “Article 29bis”) if more law is added later and for whatever reason they don’t just append it to Article 29.

It’s ugly in text, but I’m writing a document in LaTeX so I have freedom and control to do something better. At the same time, I don’t want to invent something that alienates readers. I just want to know from people who have read a lot of well typeset French what style is common. I think italicizing the “bis” is common. But what about making it a subscript or superscript? What about putting a ½ space between the bis and the number?