To inform consumers that dark chocolate products may contain milk even if not intentionally added, many chocolate manufacturers print “advisory” messages on the label. There’s quite a variety of advisory messages, such as:
“may contain milk”
“may contain dairy”
“may contain traces of milk”
“made on equipment shared with milk”
“processed in a plant that processes dairy”
“manufactured in a facility that uses milk”
FDA tested nearly 100 dark chocolate bars, including some vegan selections, for the presence of milk.
For an interesting read see:
http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm433555.htm?source=govdelivery&utm_medium=email&utm_source=govdelivery