History description 2014-03-26: Lock all vaue sets untouched since 2014-03-26
to trackingId 2014T1_2014_03_26
description:
A code specifying whether and how the participant has attested his participation
through a signature and or whether such a signature is needed.
Examples: A surgical Procedure act object (representing a procedure report)
requires a signature of the performing and responsible surgeon, and possibly other
participants. (See also: Participation.signatureText.)