diff --git a/indexer/geometry_coding.cpp b/indexer/geometry_coding.cpp
index 7706891521..ea14d863a0 100644
--- a/indexer/geometry_coding.cpp
+++ b/indexer/geometry_coding.cpp
@@ -60,7 +60,7 @@ m2::PointU PredictPointInTriangle(m2::PointU const & maxPoint,
                                   m2::PointU const & p2,
                                   m2::PointU const & p3)
 {
-  // parallelogramm prediction
+  // parallelogram prediction
   return ClampPoint(maxPoint, p1 + p2 - p3);
 }
 
diff --git a/indexer/geometry_coding.hpp b/indexer/geometry_coding.hpp
index 5b3b94aef9..57be2dc774 100644
--- a/indexer/geometry_coding.hpp
+++ b/indexer/geometry_coding.hpp
@@ -12,8 +12,8 @@
 inline uint64_t EncodeDelta(m2::PointU const & actual, m2::PointU const & prediction)
 {
   return bits::BitwiseMerge(
-        bits::ZigZagEncode(static_cast<int32_t>(actual.x) - static_cast<int32_t>(prediction.x)),
-        bits::ZigZagEncode(static_cast<int32_t>(actual.y) - static_cast<int32_t>(prediction.y)));
+          bits::ZigZagEncode(static_cast<int32_t>(actual.x) - static_cast<int32_t>(prediction.x)),
+          bits::ZigZagEncode(static_cast<int32_t>(actual.y) - static_cast<int32_t>(prediction.y)));
 }
 
 inline m2::PointU DecodeDelta(uint64_t delta, m2::PointU const & prediction)
@@ -25,18 +25,19 @@ inline m2::PointU DecodeDelta(uint64_t delta, m2::PointU const & prediction)
 //@}
 
 
-/// Predict point p0 given previous (p1, p2).
+/// Predict next point for polyline with given previous points (p1, p2).
 m2::PointU PredictPointInPolyline(m2::PointU const & maxPoint,
                                   m2::PointU const & p1,
                                   m2::PointU const & p2);
 
-/// Predict point p0 given previous (p1, p2, p3).
+/// Predict next point for polyline with given previous points (p1, p2, p3).
 m2::PointU PredictPointInPolyline(m2::PointU const & maxPoint,
                                   m2::PointU const & p1,
                                   m2::PointU const & p2,
                                   m2::PointU const & p3);
 
-/// Predict point p0 given previous (p1, p2, p3).
+/// Predict point for neighbour triangle with given
+/// previous triangle (p1, p2, p3) and common edge (p1, p2).
 m2::PointU PredictPointInTriangle(m2::PointU const & maxPoint,
                                   m2::PointU const & p1,
                                   m2::PointU const & p2,
diff --git a/indexer/geometry_serialization.cpp b/indexer/geometry_serialization.cpp
index 920a24258b..3a56f7032c 100644
--- a/indexer/geometry_serialization.cpp
+++ b/indexer/geometry_serialization.cpp
@@ -202,9 +202,9 @@ namespace serial
   }
 
   void DecodeTriangles(geo_coding::InDeltasT const & deltas,
-                      m2::PointU const & basePoint,
-                      m2::PointU const & maxPoint,
-                      geo_coding::OutPointsT & points)
+                       m2::PointU const & basePoint,
+                       m2::PointU const & maxPoint,
+                       geo_coding::OutPointsT & points)
   {
     size_t const count = deltas.size();
     ASSERT_GREATER ( count, 2, () );
@@ -220,6 +220,8 @@ namespace serial
 
     for (size_t i = 3; i < count;)
     {
+      // points 0, 1 - is a common edge
+      // point 2 - is an opposite point for new triangle to calculate prediction
       size_t trg[3];
 
       if (treeBits & 1)
@@ -253,11 +255,11 @@ namespace serial
       // push points
       points.push_back(points[trg[0]]);
       points.push_back(points[trg[1]]);
-      points.push_back( DecodeDelta(deltas[i] >> 2,
-                                    PredictPointInTriangle(maxPoint,
-                                                           points[trg[0]],
-                                                           points[trg[1]],
-                                                           points[trg[2]])));
+      points.push_back(DecodeDelta(deltas[i] >> 2,
+                                   PredictPointInTriangle(maxPoint,
+                                                          points[trg[0]],
+                                                          points[trg[1]],
+                                                          points[trg[2]])));
 
       // next step
       treeBits = deltas[i] & 3;
diff --git a/indexer/geometry_serialization.hpp b/indexer/geometry_serialization.hpp
index 0e4b030879..8a17f6eaa6 100644
--- a/indexer/geometry_serialization.hpp
+++ b/indexer/geometry_serialization.hpp
@@ -29,12 +29,12 @@ namespace serial
 
   /// @name Encode and Decode function types.
   //@{
-  typedef void (*EncodeFunT)( geo_coding::InPointsT const &,
-                              m2::PointU const &, m2::PointU const &,
-                              geo_coding::OutDeltasT &);
-  typedef void (*DecodeFunT)( geo_coding::InDeltasT const &,
-                              m2::PointU const &, m2::PointU const &,
-                              geo_coding::OutPointsT &);
+  typedef void (*EncodeFunT)(geo_coding::InPointsT const &,
+                             m2::PointU const &, m2::PointU const &,
+                             geo_coding::OutDeltasT &);
+  typedef void (*DecodeFunT)(geo_coding::InDeltasT const &,
+                             m2::PointU const &, m2::PointU const &,
+                             geo_coding::OutPointsT &);
   //@}
 
   typedef buffer_vector<uint64_t, 32> DeltasT;
@@ -196,9 +196,9 @@ namespace serial
   };
 
   void DecodeTriangles(geo_coding::InDeltasT const & deltas,
-                      m2::PointU const & basePoint,
-                      m2::PointU const & maxPoint,
-                      geo_coding::OutPointsT & triangles);
+                       m2::PointU const & basePoint,
+                       m2::PointU const & maxPoint,
+                       geo_coding::OutPointsT & triangles);
 
   template <class TSource>
   void LoadOuterTriangles(TSource & src, CodingParams const & params, OutPointsT & triangles)