A ValueList is a possible ValueType, the right side part of an Option (an assignment to a ProWiki variable). A ValueList consists of an arbitrary number of elements, separated by one of the separators "blank", "," or ";".
Of course the Variable must be designed to receive a ValueList, otherwise the behaviour may be unexpected.
It doesn't make a difference which separator you use. We suggest that you stick to a separator at least within one assigment, although mixing them won't create a problem.
A list usually is not meant to contain empty elements. Don't use a separator before or after the elements. Multiple separators between elements are treated like single separators.
There is a function SplitList that converts the string value into a Perl array.