An urban legend is usually urban folklore, true or false, but it can also be a self promotion exercise for 'celebrity status'. In common usage, urban legends are common information or disinformation which can be anything from great household cleaners to stories about non-existent animals roaming the area. The expression 'urban legend', by definition, is a skeptical term for information or the basis of information.
Examples of Urban Legend:
The food coloring blue (cochineal) is made from ground up insects (True)|
Twinkies store forever (False)
Mold in pancake mix causes anaphylactic shock (True)
The middle name of President Harry S. Truman was just the letter S (True)
The 'Bunny Man Bridge', an example of legend tripping.