diff --git a/android/jni/com/mapswithme/maps/Framework.cpp b/android/jni/com/mapswithme/maps/Framework.cpp
index 859f3229ee..957e150873 100644
--- a/android/jni/com/mapswithme/maps/Framework.cpp
+++ b/android/jni/com/mapswithme/maps/Framework.cpp
@@ -805,12 +805,10 @@ namespace android
     static jmethodID const addId = env->GetMethodID(clazz, "addMetadata", "(ILjava/lang/String;)V");
     ASSERT ( addId, () );
 
-    vector<feature::Metadata::EType> const metaTypes = metadata.GetPresentTypes();
-    for (size_t i = 0; i < metaTypes.size(); i++)
+    for (feature::Metadata::EType t : metadata.GetPresentTypes())
     {
-      feature::Metadata::EType metaType = static_cast<feature::Metadata::EType>(metaTypes[i]);
-      jstring metaString = jni::ToJavaString(env, metadata.Get(metaType));
-      env->CallVoidMethod(mapObject, addId, metaType, metaString);
+      jstring metaString = jni::ToJavaString(env, metadata.Get(t));
+      env->CallVoidMethod(mapObject, addId, t, metaString);
       // TODO use unique_ptrs for autoallocation of local refs
       env->DeleteLocalRef(metaString);
     }
@@ -847,8 +845,7 @@ pair<jintArray, jobjectArray> NativeMetadataToJavaMetadata(JNIEnv * env, feature
   for (size_t i = 0; i < metaTypes.size(); i++)
   {
     arr[i] = metaTypes[i];
-    feature::Metadata::EType metaType = static_cast<feature::Metadata::EType>(metaTypes[i]);
-    jstring metaString = jni::ToJavaString(env, metadata.Get(metaType));
+    jstring metaString = jni::ToJavaString(env, metadata.Get(metaTypes[i]));
     env->SetObjectArrayElement(j_metaValues, i, metaString);
     env->DeleteLocalRef(metaString);
   }
diff --git a/indexer/categories_holder.cpp b/indexer/categories_holder.cpp
index e573e2a0ea..e7d21d9e98 100644
--- a/indexer/categories_holder.cpp
+++ b/indexer/categories_holder.cpp
@@ -233,7 +233,7 @@ int8_t CategoriesHolder::MapLocaleToInteger(string const & locale)
     string lower = locale;
     strings::AsciiToLower(lower);
 
-    for (auto s : {"hant", "tw", "hk", "mo"})
+    for (char const * s : {"hant", "tw", "hk", "mo"})
       if (lower.find(s) != string::npos)
         return 12; // Traditional Chinese
 
diff --git a/indexer/feature_meta.hpp b/indexer/feature_meta.hpp
index bd0dfe578d..ae3d5ef9f7 100644
--- a/indexer/feature_meta.hpp
+++ b/indexer/feature_meta.hpp
@@ -8,14 +8,16 @@
 #include "std/limits.hpp"
 #include "std/algorithm.hpp"
 #include "std/vector.hpp"
+#include "std/static_assert.hpp"
+
 
 namespace feature
 {
   class Metadata
   {
-    map<uint8_t, string> m_metadata;
-
   public:
+    /// @note! Do not change values here.
+    /// Add new types to the end of list, before FMD_COUNT.
     enum EType
     {
       FMD_CUISINE = 1,
@@ -32,9 +34,12 @@ namespace feature
       FMD_TURN_LANES_FORWARD = 12,
       FMD_TURN_LANES_BACKWARD = 13,
       FMD_EMAIL = 14,
-      FMD_POSTCODE = 15
+      FMD_POSTCODE = 15,
+      FMD_COUNT
     };
 
+    STATIC_ASSERT(FMD_COUNT <= 255);
+
     bool Add(EType type, string const & s)
     {
       string & val = m_metadata[type];
@@ -54,8 +59,10 @@ namespace feature
     vector<EType> GetPresentTypes() const
     {
       vector<EType> types;
-      for (auto item : m_metadata)
-        types.push_back(static_cast<EType>(item.first));
+      types.reserve(m_metadata.size());
+
+      for (auto const & item : m_metadata)
+        types.push_back(item.first);
 
       return types;
     }
@@ -70,11 +77,12 @@ namespace feature
 
     template <class ArchiveT> void SerializeToMWM(ArchiveT & ar) const
     {
-      for (auto const & e: m_metadata)
+      for (auto const & e : m_metadata)
       {
-        uint8_t last_key_mark = (&e == &(*m_metadata.crbegin())) << 7; /// set high bit (0x80) if it last element
-        uint8_t elem[2] = {static_cast<uint8_t>(e.first | last_key_mark),
-                           static_cast<uint8_t>(min(e.second.size(), (size_t)numeric_limits<uint8_t>::max()))};
+        // set high bit if it's the last element
+        uint8_t const mark = (&e == &(*m_metadata.crbegin()) ? 0x80 : 0);
+        uint8_t elem[2] = {static_cast<uint8_t>(e.first | mark),
+                           static_cast<uint8_t>(min(e.second.size(), (size_t)kMaxStringLength))};
         ar.Write(elem, sizeof(elem));
         ar.Write(e.second.data(), elem[1]);
       }
@@ -83,12 +91,12 @@ namespace feature
     template <class ArchiveT> void DeserializeFromMWM(ArchiveT & ar)
     {
       uint8_t header[2] = {0};
-      char buffer[uint8_t(-1)] = {0};
+      char buffer[kMaxStringLength] = {0};
       do
       {
         ar.Read(header, sizeof(header));
         ar.Read(buffer, header[1]);
-        m_metadata[static_cast<uint8_t>(header[0] & 0x7F)].assign(buffer, header[1]);
+        m_metadata[ToType(header[0] & 0x7F)].assign(buffer, header[1]);
       } while (!(header[0] & 0x80));
     }
 
@@ -96,26 +104,35 @@ namespace feature
     {
       uint8_t const sz = m_metadata.size();
       WriteToSink(ar, sz);
-      if (sz)
+      for (auto const & it : m_metadata)
       {
-        for (auto const & it : m_metadata)
-        {
-          WriteToSink(ar, static_cast<uint8_t>(it.first));
-          utils::WriteString(ar, it.second);
-        }
+        WriteToSink(ar, static_cast<uint8_t>(it.first));
+        utils::WriteString(ar, it.second);
       }
     }
 
     template <class ArchiveT> void Deserialize(ArchiveT & ar)
     {
       uint8_t const sz = ReadPrimitiveFromSource<uint8_t>(ar);
+      ASSERT_LESS_OR_EQUAL(sz, FMD_COUNT, ());
+
       for (size_t i = 0; i < sz; ++i)
       {
-        uint8_t const key = ReadPrimitiveFromSource<uint8_t>(ar);
+        EType const key = ToType(ReadPrimitiveFromSource<uint8_t>(ar));
         string value;
         utils::ReadString(ar, value);
         m_metadata.insert(make_pair(key, value));
       }
     }
+
+  private:
+    static EType ToType(uint8_t key)
+    {
+      ASSERT(key > 0 && key < FMD_COUNT, (key));
+      return static_cast<EType>(key);
+    }
+
+    enum { kMaxStringLength = 255 };
+    map<EType, string> m_metadata;
   };
 }