Using the header facet of the af:column tag, developers can add components to the table header, for example to indicate the component to be excluded from printing or export to Excel. The side effect of adding a command item to a table header is when the table column is sortable.
In this case, selecting the component, for example an instance of af:selectBooleanCheckBox , will also trigger sorting on the table, which you don't want to happen until users explicitly ask for this.
<af:selectBooleanCheckbox id="sbc2" text="FirstName"
value="..." autoSubmit="true"><af:clientListener method="stopBubbling" type="click"/>