Logo usage

The systems / projects logo should appear once per page, and be positioned aligned left, and vertically centered within the banner. The Index or about page is an exception to this rule, where a more prominent piece of branding (often being the logo) is commonly presented accompanied by an introductory text
The system’s style should correlate with the color of the logo so as to create brand association
Provided logos should always be a clickable link which directs to the associated website

Usability guidelines