Usage of Historical Characters

Historical Characters born after the PoD pose a problem for authors, as the author must find a way to deal with them. There are many different methods of using these HCs, sometimes influenced by the religion of the author.

Which ones are "bad" or "good" is highly debatable, as is plausibility.
 * Fame Equals Birth
 * In Name Only
 * In Personality Only
 * Alternate Timeline Brother
 * Only OCs