Universal citation has been implemented in various ways in Arkansas, Colorado, Illinois, Louisiana, Maine, Mississippi, Montana, New Mexico, North Carolina, North Dakota, Ohio, Oklahoma, South Dakota, Tennessee, Utah, Wisconsin, and Wyoming.
Notably, Arkansas and Wisconsin rejected universal citation upon initial consideration. Later, they reconsidered it, and have now adopted and implemented universal citation.
Neutral formats for case law citations, without parallel citation, are standard in Australia, Canada, and the United Kingdom.