Function align 

pub fn align(
    sisu_first_names: Option<&str>,
    sisu_last_name: Option<&str>,
    account_first_name: Option<&str>,
    account_last_name: Option<&str>,
) -> Option<NameReplacement>

The name linking gives the account, or None when it keeps its own: it already uses Sisu’s name, or Sisu holds none.

The name is kept when every name in the account’s first name is one of Sisu’s first names and the last names are the same, ignoring case. Otherwise it is replaced, with any first names that are only misspelt (case, diacritics, a typo or two) offered back in Sisu’s spelling.