For example, words in bold, italic or underlined, or footnotes are always treated the same way for any ebook.
"40 years / 40 años / 40 ans"
Marie Lebert
Elsewhere in the text, occasional words in italic typeface have been marked up with underscores.
"The Critic in the Orient"
George Hamlin Fitch
The white surface, with a silver boss in the centre, surrounded by first a white and then a red circle, and the purple border, showed that he belonged to the Tertiani or third italic Legion, which had been stationed in Africa since the time of Augustus.
"Callista"
John Henry Cardinal Newman