NCIt definition : Information exists but is not provided due to security or privacy concerns.;
Alternative definition : CDISC: There is information on this item available but it has not been provided by
the sender due to security, privacy or other reasons. There may be an alternate mechanism
for gaining access to this information. Warning: Using this null flavor does provide
information that may be a breach of confidentiality, even though no detail data is
provided. Its primary purpose is for those circumstances where it is necessary to
inform the receiver that the information does exist without providing any detail.
(ISO);