How-to-deprecate.md

 So you want to deprecate something in OTB? Follow the guide:
 
-#### A C++ class (WIP)
+#### A C++ class
 
 In the doxygen documentation of the class, add the `\deprecated` keyword.
 
-In the class declaration, use the `[[deprecated]]` attribute. If the class declaration already has an export macro, use the macro `_DEPRECATED_EXPORT`.
+#### A method of a C++ class or free function
 
-#### A method of a C++ class (WIP)
+In the doxygen documentation of the method, add the `\deprecated` keyword.
 
-Use the `[[deprecated]]` attribute.
+#### A part of the Python API
 
-#### A part of the Python API (WIP)
 
+#### An OTB application
 
-#### An OTB application (WIP)
-
-Add the tag deprecated:
+Add the deprecated tag to `DoInit()` section:
 
 ```
 AddDocTag(Tags::Deprecated);
@@ -40,8 +38,7 @@ otb_module(OTBDeprecatedModuleName
     "${DOCUMENTATION}"
 )
 ```
-
-One need to make sure that the deprecated module is not a mandatory dependency of any other module. One can still allow the module to be use thanks to the `OPTIONAL_DEPENDS` key word :
+One need to make sure that the deprecated module is not a mandatory dependency of any other module. One can still allow the module to be used thanks to the `OPTIONAL_DEPENDS` key word :
 ```CMake
 set(DOCUMENTATION "Some documentation")
 otb_module(OTBDModuleName
@@ -61,12 +58,4 @@ otb_module(OTBDModuleName
 )
 ```
 
-Please make sure that all of the classes in the module have the `ModuleName_DEPRECATED_EXPORT` and the Doxygene tag `\deprecated`.
-
-#### How to disable deprecated features when `OTB_USE_DEPRECATED=OFF`?
-
-For an example, see [this MR](https://gitlab.orfeo-toolbox.org/orfeotoolbox/otb/merge_requests/236/diffs)
-
-* If you deprecate a whole module, it will be disabled during configure step.
-* If you want to deprecate a C++ class and the associated tests: use variable `OTB_USE_DEPRECATED` to protect the inclusion of this class in `src/CMakeLists.txt` and `test/CMakeLists.txt`
-* in otbConfigure.h, there is a macro `OTB_USE_DEPRECATED`, which is defined when CMake option `OTB_USE_DEPRECATED=ON`. Use it to disable portions of code in `test/otbXXXTestDriver.cxx` for instance
+Please make sure that all of the classes, methods and free functions in the module have the `ModuleName_DEPRECATED_EXPORT` and the Doxygene tag `\deprecated`.