There are a large number of security patterns encapsulating reusable solutions to recurrent security problems. However, catalogs of security patterns are not enough because the designer does not know when and where to apply them, especially in a large complex system. There is a need to conduct more precise classifications of security patterns. We analyze here ways to represent security patterns using specialized models for their precise classification. We define two new types of models, one that describes how a security pattern relates to several classification dimensions (Dimension Graph), and another that describes how security patterns relate to each other (Pattern Graphs). We show these ideas with examples from security patterns.