As suspected I was slightly confused, but the result is the same. By the SQL standard, quoted names are treated case-sensitive, unquoted names are treated as upper case, when being compared. (This may be different in MySQL). If you always quote names there is no problem, but if you don't your lower case unquoted name (treated as upper case) will not match your lower case quoted name.

http://en.wikibooks.org/wiki/SQL_Dialects_Reference/Data_structure_definition/Delimited_identifiers

Also http://www.contrib.andrew.cmu.edu/~shadow/sql/sql1992.txt Page 87:
```
            A <regular identifier> and a <delimited identifier> are equiva-
            lent if the <identifier body> of the <regular identifier> (with
            every letter that is a lower-case letter replaced by the equiva-
            lent upper-case letter or letters) and the <delimited identifier
            body> of the <delimited identifier> [...] compare equally [...].
```