diff --git a/src/schema.hpp b/src/schema.hpp
index 7d6e486..9c7114b 100644
--- a/src/schema.hpp
+++ b/src/schema.hpp
@@ -15,7 +15,12 @@
 #include "ast.hpp"
 
 namespace yang {
+enum class ContainerTraits {
+    Presence,
+    None,
+};
 struct container {
+    yang::ContainerTraits m_presence;
 };
 struct list {
     std::set<std::string> m_keys;
@@ -23,7 +28,6 @@
 }
 
 
-
 using NodeType = boost::variant<yang::container, yang::list>;
 
 
@@ -42,11 +46,12 @@
     bool nodeExists(const std::string& location, const std::string& name) const;
 
     bool isContainer(const path_& location, const std::string& name) const;
-    void addContainer(const std::string& location, const std::string& name);
+    void addContainer(const std::string& location, const std::string& name, yang::ContainerTraits isPresence = yang::ContainerTraits::None);
     const std::set<std::string>& listKeys(const path_& location, const std::string& name) const;
     bool listHasKey(const path_& location, const std::string& name, const std::string& key) const;
     bool isList(const path_& location, const std::string& name) const;
     void addList(const std::string& location, const std::string& name, const std::set<std::string>& keys);
+    bool isPresenceContainer(const path_& location, const std::string& name) const;
 
 private:
     const std::unordered_map<std::string, NodeType>& children(const std::string& name) const;