Linking domains owned by the same company or person. It should not be a problem if the websites are topically related and there are not many links. Exact match anchor text and site-wide linking should be avoided to reduce the risk of penalty.
About the Author: Chad Klingensmith
Chad is a Sr. SEO Strategist for Rio SEO. He has over 10 years of experience in the digital marketing vertical. He enjoys researching and applying cutting edge marketing strategies to help clients achieve optimal online visibility.