IAB Rich Media Guidelines

Guidelines for rich media from the Interactive Advertising Bureau (IAB). Includes in-page and out-of-page specifications for rich media advertising, providing recommendations for unit format, size, weight (kb), and frequency of display. All web publishers are urged to voluntarily adopt these recommendations.

More information about them, from the website:

These updated Display Creative Guidelines are the work-product of an exhaustive nine-month cross-industry working group effort to bring the industry inline with the creative demands of brand advertisers. The IAB had two overriding goals for this update:

Issue guidelines that empower creative shops to exercise the limits of their imagination, only tempering creativity as it relates to positive consumer experience; and
Further simplify the digital supply chain by making these new guidelines easily accessible, adoptable and understandable.

Visit IAB - Rich Media Creative Guidelines