Like mentioned by Andrei Pavlenko after merging pullrequest #1206, a wrong

ReST directive was used. Also fixed some other ReST directives that were
not correct and removed some warnings during buildbot checks.

modules/features2d/doc/common_interfaces_of_descriptor_extractors.rst

@@ -9,10 +9,10 @@ represented as vectors in a multidimensional space. All objects that implement t
 descriptor extractors inherit the
 :ocv:class:`DescriptorExtractor` interface.
 
-.. Sample code::
+.. note::
 
-   * : An example explaining keypoint extraction can be found at opencv_source_code/samples/cpp/descriptor_extractor_matcher.cpp
-   * : An example on descriptor evaluation can be found at opencv_source_code/samples/cpp/detector_descriptor_evaluation.cpp
+   * An example explaining keypoint extraction can be found at opencv_source_code/samples/cpp/descriptor_extractor_matcher.cpp
+   * An example on descriptor evaluation can be found at opencv_source_code/samples/cpp/detector_descriptor_evaluation.cpp
 
 DescriptorExtractor
 -------------------
@@ -141,6 +141,6 @@ Strecha C., Fua P. *BRIEF: Binary Robust Independent Elementary Features* ,
         ...
     };
 
-.. Sample code:: 
+.. note::
 
-   * : A complete BRIEF extractor sample can be found at opencv_source_code/samples/cpp/brief_match_test.cpp
+   * A complete BRIEF extractor sample can be found at opencv_source_code/samples/cpp/brief_match_test.cpp

modules/features2d/doc/common_interfaces_of_descriptor_matchers.rst

@@ -9,11 +9,11 @@ that are represented as vectors in a multidimensional space. All objects that im
 descriptor matchers inherit the
 :ocv:class:`DescriptorMatcher` interface.
 
-.. Sample code::
+.. note::
 
-   * : An example explaining keypoint matching can be found at opencv_source_code/samples/cpp/descriptor_extractor_matcher.cpp
-   * : An example on descriptor matching evaluation can be found at opencv_source_code/samples/cpp/detector_descriptor_matcher_evaluation.cpp
-   * : An example on one to many image matching can be found at opencv_source_code/samples/cpp/matching_to_many_images.cpp
+   * An example explaining keypoint matching can be found at opencv_source_code/samples/cpp/descriptor_extractor_matcher.cpp
+   * An example on descriptor matching evaluation can be found at opencv_source_code/samples/cpp/detector_descriptor_matcher_evaluation.cpp
+   * An example on one to many image matching can be found at opencv_source_code/samples/cpp/matching_to_many_images.cpp
 
 DMatch
 ------

modules/features2d/doc/common_interfaces_of_feature_detectors.rst

@@ -8,9 +8,9 @@ between different algorithms solving the same problem. All objects that implemen
 inherit the
 :ocv:class:`FeatureDetector` interface.
 
-.. Sample code::
+.. note::
 
-   * : An example explaining keypoint detection can be found at opencv_source_code/samples/cpp/descriptor_extractor_matcher.cpp
+   * An example explaining keypoint detection can be found at opencv_source_code/samples/cpp/descriptor_extractor_matcher.cpp
 
 
 KeyPoint

modules/features2d/doc/common_interfaces_of_generic_descriptor_matchers.rst

@@ -11,11 +11,11 @@ Every descriptor with the
 :ocv:class:`VectorDescriptorMatcher` ).
 There are descriptors such as the One-way descriptor and Ferns that have the ``GenericDescriptorMatcher`` interface implemented but do not support ``DescriptorExtractor``.
 
-.. Sample code::
+.. note::
 
-   * : An example explaining keypoint description can be found at opencv_source_code/samples/cpp/descriptor_extractor_matcher.cpp
-   * : An example on descriptor matching evaluation can be found at opencv_source_code/samples/cpp/detector_descriptor_matcher_evaluation.cpp
-   * : An example on one to many image matching can be found at opencv_source_code/samples/cpp/matching_to_many_images.cpp
+   * An example explaining keypoint description can be found at opencv_source_code/samples/cpp/descriptor_extractor_matcher.cpp
+   * An example on descriptor matching evaluation can be found at opencv_source_code/samples/cpp/detector_descriptor_matcher_evaluation.cpp
+   * An example on one to many image matching can be found at opencv_source_code/samples/cpp/matching_to_many_images.cpp
 
 GenericDescriptorMatcher
 ------------------------

modules/features2d/doc/feature_detection_and_description.rst

@@ -3,9 +3,9 @@ Feature Detection and Description
 
 .. highlight:: cpp
 
-.. Sample code::
+.. note::
 
-   * : An example explaining keypoint detection and description can be found at opencv_source_code/samples/cpp/descriptor_extractor_matcher.cpp
+   * An example explaining keypoint detection and description can be found at opencv_source_code/samples/cpp/descriptor_extractor_matcher.cpp
 
 FAST
 ----
@@ -55,9 +55,9 @@ Maximally stable extremal region extractor. ::
 The class encapsulates all the parameters of the MSER extraction algorithm (see
 http://en.wikipedia.org/wiki/Maximally_stable_extremal_regions). Also see http://code.opencv.org/projects/opencv/wiki/MSER for useful comments and parameters description.
 
-.. Sample code::
+.. note::
 
-   * : PYTHON : A complete example showing the use of the MSER detector can be found at opencv_source_code/samples/python2/mser.py
+   * (Python) A complete example showing the use of the MSER detector can be found at opencv_source_code/samples/python2/mser.py
 
 
 ORB
@@ -166,9 +166,9 @@ Class implementing the FREAK (*Fast Retina Keypoint*) keypoint descriptor, descr
 
 .. [AOV12] A. Alahi, R. Ortiz, and P. Vandergheynst. FREAK: Fast Retina Keypoint. In IEEE Conference on Computer Vision and Pattern Recognition, 2012. CVPR 2012 Open Source Award Winner.
 
-.. Sample code::
+.. note::
 
-   * : An example on how to use the FREAK descriptor can be found at opencv_source_code/samples/cpp/freak_demo.cpp
+   * An example on how to use the FREAK descriptor can be found at opencv_source_code/samples/cpp/freak_demo.cpp
 
 FREAK::FREAK
 ------------

modules/features2d/doc/object_categorization.rst

@@ -5,11 +5,11 @@ Object Categorization
 
 This section describes approaches based on local 2D features and used to categorize objects.
 
-.. Sample code:: 
+.. note::
 
-   * : A complete Bag-Of-Words sample can be found at opencv_source_code/samples/cpp/bagofwords_classification.cpp
+   * A complete Bag-Of-Words sample can be found at opencv_source_code/samples/cpp/bagofwords_classification.cpp
 
-   * : PYTHON : An example using the features2D framework to perform object categorization can be found at opencv_source_code/samples/python2/find_obj.py
+   * (Python) An example using the features2D framework to perform object categorization can be found at opencv_source_code/samples/python2/find_obj.py
 
 BOWTrainer
 ----------