Escaped International characters?

I am looking at some PHP code where there are translation strings. For French there are characters that I ha开发者_StackOverflow中文版ve never seen before and I am asking if someone could shed a light.

These strings are used as HTML output, but also as body text to send emails.

È = é
Ë = è
‡ = à
Í = ê
...

The RHS (é, è, à, ê) are in ISO-8859-1 (and Unicode) encoding.

The LHS (È, Ë, ‡, Í) are the corresponding characters in Mac-Roman encoding with the same code-point.