In reply to SteakAndAle:
In Spain we don't use the UIAA grades, mainly are the french grades with roman numbers.
Depending the area and the author, you can find the normal numbers or roman numbers (p.e. When I produce a guidebook, I prefer to use normal numbers to have the same format in all the guidebook).
Them, We don't normally use thefrench format below 6a (taht means, we don't add a, b, c, in grades 5, 4, 3, 2), we prefer to add only a + (5 or 5+), but comparing grades 5+ should be a 5c, and a 5 close to 5b (more or less).
Hope it will be a help for you.
David Mora
Mountain Guide