We use text features such as textual delimiters, keywords, constants or text patterns, which we call anchors, to identify data regions on a web page. Using these anchors, we create patterns for [the] data regions and match them in a mixed bottom-up and top-down manner.
The first sentence speaks about data regions in general. Could ti be in the case of the second sentence? or I'd better to use "the" to say these data regions are the same data regions we pointed in the previous sentence?