BPMN21 — Attributes of Transaction Element

According to the class diagram of Sub-Process (Figure 10.29, page 181), Transaction has two attributes (protocol and transaction). However, in Table 10.21 on page 185 only method is mentioned (transaction missing).

In addition, the class diagram specifies that the data type of method is string. Table 10.21, however, defines that the data type is of TransactionMethod.

Since an element TransactionMethod is not defined in any metamodel, I would suggest to use data type string. In addition, protocol could be inserted in Table 10.21 with a cardinality of [0..1] or [1].