<tml:[All tags] appendvar ="variable-name">
If a variable of the given name is already defined then this attribute will append the value of the current tag result to this variable, preserving its type (session var, portlet var etc.). The value will be appended as a list element to the variable value. The value of the variable therefor will become a List.
If the variable is not already defined then a normal WebTML variable of that name is created and initialized with the value of the tag result.
If the value of the tag result is itself a List (like on <tml:foreach>) then all elements of that list will be appended to the WebTML variable.