BPMN21 — Page 221. Nonexistent attribute “optional” mentioned

It says
“The “optional” attribute defines if a DataInput is valid even if the state is “unavailable”. The default value is false. If the value of this attribute is true, then the execution of the Activity will not begin until a value is assigned to the DataInput element, through the corresponding Data Associations.”

Problem: The “optional” attribute of “DatInput” is mentioned, but it is not shown in any Table or Figure (in particular Figure 10.59, p. 221; and Table 10.59, p. 222).

This paragraph should be removed; or the attribute “optional” should be added in Table 10.59 and Figure 10.59.