CentOS Links Visual Style Guide.
This is a common text link style
This is a common nonexistant text link style
http://www.centos.org/. This is the "www" and "http" link style. It is generally used to link external sites.
centos-devel@centos.org. This is the "mailto" link style. It is generally used to display email addresses.
header-bg.jpg. This is the "attachment" link style. It is generally used to display an attachment.