What does the term 'spillage' refer to?

The term 'spillage' specifically refers to a security incident involving classified data where sensitive information is exposed or misclassified. It typically occurs when classified data is unintentionally released into a less secure or unclassified environment. This could happen through various means such as accidental email distribution, improper data handling, or storage in unsecured areas. The crucial aspect of spillage is its focus on the sensitivity and classification of the data that is mishandled, which can lead to significant security risks and breaches of confidentiality for organizations that manage sensitive information.

In this context, the other options present definitions that, while relevant to data security, do not encapsulate the specific nature of 'spillage.' Data transfer between secure locations refers to authorized data movement, loss of data confidentiality pertains to the broader concept of unauthorized disclosure, and unauthorized access involves breaches in system security rather than the classification mishaps associated with spillage.