The target is any container through which you want to search.
The source is any container, variable or string for which you   want to search. If the source string begins with the “<”  character then the search is for any match of the source in the target. (The “<” character is not treated as part of the string.) Otherwise, the search is for an exact match of the  source with an item in the target. The afterLine is an optional parameter specifying the line after which to begin searching. The afterItem is an optional parameter specifying the item after which to begin searching.