The Requirement Type field specifies the requirements on the presence or absence of the Content Item or included Template.
Note: There is typically no need to specify Requirement Type separately for SCU and SCP of the Basic SR SOP Classes, because the SCP is required to support the entire content of any SR Document it receives. Therefore, for Basic SR SOP Classes, Requirement Type effectively only applies to the SCU.
The following symbols are used:
M – Mandatory. Shall be present.
MC – Mandatory Conditional. Shall be present if the specified condition is satisfied.
U – User Option. May or may not be present.
UC – User Option Conditional. May not be present. May be present according to the specified condition.
Note: There is an interaction between the VM and the Requirement Type with respect to the number of times that a content item (or included Template) may actually be present, as follows:
Req Type VM Actual number of occurences in the content tree
M 1 1
M 1-n 1 to n
U 1 0 or 1
U 1-n 0 to n