diff --git a/docs.it4i/software/viz/insitu.md b/docs.it4i/software/viz/insitu.md
index e0e1fb2e1e8b66769f081d2b2439c2f5f0aca964..c8441999f5565ff4b2b817127d4919849b2b4f16 100644
--- a/docs.it4i/software/viz/insitu.md
+++ b/docs.it4i/software/viz/insitu.md
@@ -6,7 +6,7 @@ In situ visualization is a possibility how to visualize your data while your com
 
 To leverage the possibilities of the in situ visualization by Catalyst library, you have to write an adaptor code that will use the actual data from your simulation and process them in the way they can be passed to ParaView for visualization. We provide a simple example of such simulator/adaptor code that bind together to provide the in situ visualization.
 
-Detailed description of the Catalyst API can be found [here][catalyst_guide]. We restrict ourselves to provide more of an overall description of the code parts together with building description, and startup description to run it all on the cluster.  
+Detailed description of the Catalyst API can be found [here][catalyst_guide]. We restrict ourselves to provide more of an overall description of the code together with specifications for building, and explanation about how to run the code on the cluster.  
  
 
 ## Installed Version
@@ -15,7 +15,7 @@ The Catalyst library is part of the ParaView module. More about ParaView can be
 
 ## Usage
 
-All code concerning the simulator/adaptor are available to download from [here][code]. It is a package that contains following files: CMakeLists.txt, FEAdaptor.h, FEAdaptor.cxx, FEDataStructures.h, FEDataStructures.cxx, FEDriver.cxx and feslicescript.py.
+All code concerning the simulator/adaptor are available to download from [here][code]. It is a package with the following files: CMakeLists.txt, FEAdaptor.h, FEAdaptor.cxx, FEDataStructures.h, FEDataStructures.cxx, FEDriver.cxx and feslicescript.py.
 
 First unpack the [code][code]. You can do it by
 
@@ -23,8 +23,7 @@ First unpack the [code][code]. You can do it by
 $ tar xvf package_name
 ```
 
-
-Use CMake to manage the build process but first load the appropriate modules (CMake, compiler, ParaView) by
+Use CMake to manage the build process but before that load the appropriate modules (CMake, compiler, ParaView) by
 
 ```console
 $ ml CMake intel/2017a ParaView/5.6.0-intel-2017a-mpi
@@ -37,15 +36,27 @@ $ cmake ../
 ```
 
 Now you can build the simulator/adaptor code using make
+
 ```console
 $ make
 ```
 
-It will generate the CxxFullExampleAdaptor executable file. This can be later run together with ParaView and provide the in situ visualization.
+It will generate the CxxFullExampleAdaptor executable file. This can be later run together with ParaView and it will provide the in situ visualization example.
 
 ## Code explanation
- 
 
+Provided example is a simple MPI program. Main executing part is written in FEDriver.cxx. It is a simulator code that creates computational grid   
+
+
+```javascript
+#include ahoj.h
+
+int main() {
+
+
+return 0;
+}
+```
 
 mpirun -n 2 ./CxxFullExample 30 30 30 ../SampleScripts/feslicescript.py