[arch-general] same packages with different letter case in names?

Hello, All! What difference between x86_64/koffice-l10n-en_GB-1.6.3-2.pkg.tar.gz x86_64/koffice-l10n-en_gb-1.6.3-2.pkg.tar.gz x86_64/koffice-l10n-pt_BR-1.6.3-2.pkg.tar.gz x86_64/koffice-l10n-pt_br-1.6.3-2.pkg.tar.gz in [extra]?