We use a number of standardized User Attributes which contain a comma-separated list of values. However if we use the "specified attribute value" selection criteria and use operator "contains" then the value will we request will match any super-string values. For example a requested value of "linux" will match "linux32" or "linux64" etc. I can achieve the desired result using a "script evaluates to true" criteria with a script like this

util.split(node.getAttribute("attrName","NO_ATTR_SPECIFIED").contains("value")

But it'd be nice to have that built-in so that new people who aren't as familiar with the script API don't get caught but the substring problem.