diff --git a/mo/src/problems/partition/moBinaryPartition.h b/mo/src/problems/partition/moBinaryPartition.h
index 2fedb50ef..7fd53bce0 100644
--- a/mo/src/problems/partition/moBinaryPartition.h
+++ b/mo/src/problems/partition/moBinaryPartition.h
@@ -4,30 +4,76 @@
 
 #include <eo>
 
+/** A partition of a binary space.
+ *
+ * This data structure defines a grouping of the elements of a multi-dimensional
+ * set in a space of boolean numbers.
+ * \f[
+ *      \mathrm{1}^n = \bigcup_{i=1}^n \{0,1\}_i
+ * \f]
+ * Elements of the set may be either "selected" (in the set S) or "rejected" (in the set R).
+ * \f[
+ *      (S \in \mathrm{1}^m) \cup (R \in \mathrm{1}^k) \in \mathrm{1}^n,\; n=m+k
+ * \f]
+ * Elements are referred to by their index in the set (hereby named "atoms").
+ *
+ * This representation is useful if your problem can be defined has selecting
+ * a subset of elements that optimize some objective function.
+ *
+ * The core data structures are two ordered sets of unique atoms,
+ * the union of which is guaranteed to have the correct dimension.
+ */
 template<class FitT>
 class moBinaryPartition : public EO<FitT>
 {
     public:
+        /** The type for indices. */
         using AtomType = size_t;
+
+        /** The data structures holding the indices. */
         using ContainerType = std::set<AtomType>;
 
+        /** The set of selected atoms. */
         ContainerType selected;
+
+        /** The set of not-selected atoms. */
         ContainerType rejected;
 
-        /** Constructor
+        /** Consistent constructor
          *
-         * @param total_nb_genes Total number of possible genes from whith to select.
+         * Put all `total_nb_atoms` indices in the @ref rejected set.
+         * Indices starts at zero and fill the set in increasing order.
+         *
+         * @param total_nb_atoms Total number of possible atoms from whith to select.
          */
-        moBinaryPartition( const size_t total_nb_genes )
+        moBinaryPartition( const size_t total_nb_atoms )
         {
             // Fill the rejected list with all possible gene indices,
             // starting from zero.
-            for(size_t i = 0; i < total_nb_genes; ++i) {
+            for(size_t i = 0; i < total_nb_atoms; ++i) {
                 rejected.insert(i);
             }
-            // No selected.
+            // None selected.
         }
 
+        /** Empty constructor
+         *
+         * Do not fill the @ref rejected set.
+         * You are responsible for making it consistent after instantiation.
+         *
+         * @warning If you do not fill at least the @ref rejected set,
+         *          errors will be raised whe trying to @ref select or @ref reject.
+         */
+        moBinaryPartition()
+        { }
+
+        /** Move one atom in the @ref selected set.
+         *
+         * That is: erase the atom from @ref rejected,
+         * insert it in @ref selected.
+         *
+         * @note In debug mode, double check that elements were actually moved.
+         */
         void select(const size_t atom) {
             assert(not selected.contains(atom));
 
@@ -44,6 +90,13 @@ class moBinaryPartition : public EO<FitT>
             assert(has_inserted);
         }
 
+        /** Move one atom in the @ref rejected set.
+         *
+         * That is: insert the atom in @ref rejected,
+         * erase it from @ref selected.
+         *
+         * @note In debug mode, double check that elements were actually moved.
+         */
         void reject(const size_t atom) {
             assert(not rejected.contains(atom));
 
@@ -95,6 +148,7 @@ class moBinaryPartition : public EO<FitT>
             assert(rejected.size() == size);
         }
 
+        /** Returns true if all sets are equals. */
         bool operator==(const moBinaryPartition& other) {
             return this->selected == other.selected
                and this->rejected == other.rejected;
diff --git a/mo/src/problems/partition/moBinaryPartitionSwapNeighbor.h b/mo/src/problems/partition/moBinaryPartitionSwapNeighbor.h
index 86e97a74d..af7449398 100644
--- a/mo/src/problems/partition/moBinaryPartitionSwapNeighbor.h
+++ b/mo/src/problems/partition/moBinaryPartitionSwapNeighbor.h
@@ -6,25 +6,53 @@
 
 #include "moBinaryPartition.h"
 
+/** Stable neighbor for a binary partition.
+ *
+ * Models how to move from a solution to a neighbor,
+ * by swaping one selected atom for one rejected atom.
+ * The number of selected atoms is thus guaranteed to be stable.
+ *
+ * The core data structure is two atoms:
+ * - the selected one,
+ * - the rejected one.
+ */
 template<class EOT, class Fitness=typename EOT::Fitness>
 class moBinaryPartitionSwapNeighbor :
             public moBackableNeighbor<EOT,double>//,
-            // public moIndexNeighbor<EOT,double>
+            // public moIndexNeighbor<EOT,double> // FIXME see if we can model that.
 {
     public:
+        /** Shortcut for Atom’s type. */
         using AtomType = typename EOT::AtomType;
+
+        /** Shortcut for container’s type. */
         using ContainerType = typename EOT::ContainerType;
+
+        /** Shortcut for fitness. */
         using moBackableNeighbor<EOT, Fitness>::fitness;
+
         // using moIndexNeighbor<EOT, Fitness>::key;
         // using moIndexNeighbor<EOT, Fitness>::index;
 
+        /** Consistent constructor.
+         *
+         * Will ensure that the dimension of the partition does not change.
+         *
+         * @param _selected_nb Number of selected atoms to maintain.
+         */
         moBinaryPartitionSwapNeighbor( const size_t _selected_nb ) :
-            selected_nb(_selected_nb),
-            is_set(false)
+            selected_nb(_selected_nb)
+            #ifndef NDEBUG
+                , is_set(false)
+            #endif
         {
             assert(selected_nb > 0);
         }
 
+        /** Apply the currently stored move.
+         *
+         * That is: reject one atom and select one other.
+         */
         virtual void move(EOT& solution) override {
             assert(is_set);
             // Swap the two atoms.
@@ -35,6 +63,10 @@ class moBinaryPartitionSwapNeighbor :
             solution.invalidate();
         }
 
+        /** Apply the opposite of the currently stored move.
+         *
+         * That is: reject the selected atom, and select the rejected one.
+         */
         virtual void moveBack(EOT& solution) override {
             assert(is_set);
             solution.reject(this->select);
@@ -44,6 +76,11 @@ class moBinaryPartitionSwapNeighbor :
             solution.invalidate();
         }
 
+        /** Set the considered atoms.
+         *
+         * @param in The selected atom.
+         * @param out The rejected atom.
+         */
         void set(AtomType in, AtomType out) {
             this->select = in;
             this->reject = out;
@@ -52,11 +89,16 @@ class moBinaryPartitionSwapNeighbor :
             #endif
         }
 
+        /** Get the considered atom.
+         *
+         * @returns A pair of atoms, the first being the selected atom, the second being the rejected one.
+         */
         std::pair<AtomType,AtomType> get() {
             assert(is_set);
             return std::make_pair(select, reject);
         }
 
+        /** Returns true if this neighbor has the same selected & rejected atoms than the given neighbor. */
         virtual bool equals(moBinaryPartitionSwapNeighbor<EOT,Fitness>& neighbor) {
             auto [in, out] = neighbor.get();
             return this->select == in and this->reject == out;
@@ -66,6 +108,7 @@ class moBinaryPartitionSwapNeighbor :
             return "moBinaryPartitionSwapNeighbor";
         }
 
+        /** Fancy print. */
         virtual void printOn(std::ostream& out) const override {
             assert(is_set);
             out << selected_nb
@@ -78,10 +121,21 @@ class moBinaryPartitionSwapNeighbor :
 #else
     protected:
 #endif
+        /** Fixed dimension of the handled solutions. */
         const size_t selected_nb;
+
+        /** Selected atom. */
         AtomType select;
+
+        /** Rejected atom. */
         AtomType reject;
+
         #ifndef NDEBUG
+            /** Sanity flag.
+             *
+             * Used in debug builds to ensure that the neighbor
+             * have been set before being used.
+             */
             bool is_set;
         #endif
 };
diff --git a/mo/src/problems/partition/moBinaryPartitionSwapNeighborhood.h b/mo/src/problems/partition/moBinaryPartitionSwapNeighborhood.h
index e92382357..694576732 100644
--- a/mo/src/problems/partition/moBinaryPartitionSwapNeighborhood.h
+++ b/mo/src/problems/partition/moBinaryPartitionSwapNeighborhood.h
@@ -5,13 +5,32 @@
 #include <mo>
 #include "moBinaryPartition.h"
 
+/** Stable neighborhood for binary partitions.
+ *
+ * This generates all neighbors of a binary partition
+ * that have the same dimension than the considered solution.
+ * I.e. it enumerates all the swaps of two atoms
+ * between the selected and rejected sets.
+ *
+ * The core data structure is two indices:
+ * - one for the position within the selected set of a binary partition,
+ * - the other for the position within the rejected set.
+ *
+ * The neighborhood is defined as enumerating the neighbors,
+ * first by going over the rejected atoms (outer loop),
+ * then by iterating over the selected atoms (inner loop).
+ */
 template <class EOT, class Fitness=typename EOT::Fitness>
 class moBinaryPartitionSwapNeighborhood : public moNeighborhood<moBinaryPartitionSwapNeighbor<EOT, Fitness> >
 {
     public:
+        /** Shortcut for neighbor's type. */
         using Neighbor = moBinaryPartitionSwapNeighbor<EOT, Fitness>;
+
+        /** Shortcut for Atom’s type. */
         using AtomType = typename EOT::AtomType;
 
+        /** Get the currently pointed selected atom. */
         AtomType selected(EOT& from, const size_t i_select) {
             typename EOT::ContainerType::iterator
                 it = std::begin(from.rejected);
@@ -19,6 +38,7 @@ class moBinaryPartitionSwapNeighborhood : public moNeighborhood<moBinaryPartitio
             return *it;
         }
 
+        /** Get the currently pointed rejected atom. */
         AtomType rejected(EOT& from, const size_t j_reject) {
             typename EOT::ContainerType::iterator
                 it = std::begin(from.selected);
@@ -26,6 +46,11 @@ class moBinaryPartitionSwapNeighborhood : public moNeighborhood<moBinaryPartitio
             return *it;
         }
 
+        /** Initialize the neighborhood.
+         *
+         * This actually make the neighborhood point to the first possible swap:
+         * between the first selected atom and the first rejected atom.
+         */
         virtual void init(EOT& from, Neighbor& to) override {
             i_select = 0;
             j_reject = 0;
@@ -41,6 +66,7 @@ class moBinaryPartitionSwapNeighborhood : public moNeighborhood<moBinaryPartitio
             to.set(in, out);
         }
 
+        /** Point to the next neighbor. */
         virtual void next(EOT& from, Neighbor& to) override {
             // If last item of the inner loop.
             if( i_select == from.rejected.size()-1 ) {
@@ -66,9 +92,8 @@ class moBinaryPartitionSwapNeighborhood : public moNeighborhood<moBinaryPartitio
             );
         }
 
+        /** Returns true if there is more neighbors to be enumerated. */
         virtual bool cont(EOT& from) override {
-            // Outer loop on selected,
-            // inner loop on rejected.
             // std::clog << "cont neighborhood?"
             //     << " " << j_reject << "(-" << rejected(from, j_reject) << ")/" << from.selected.size()
             //     << " " << i_select << "(-" << selected(from, i_select) << ")/" << from.rejected.size()
@@ -90,6 +115,10 @@ class moBinaryPartitionSwapNeighborhood : public moNeighborhood<moBinaryPartitio
             }
         }
 
+    /** Returns true if there is actual neighbors in the neighborhood.
+     *
+     * Essentially just tells if the rejected set is not empty.
+     */
     virtual bool hasNeighbor(EOT& solution) override {
         return solution.rejected.size() > 0;
     }
@@ -103,6 +132,9 @@ class moBinaryPartitionSwapNeighborhood : public moNeighborhood<moBinaryPartitio
 #else
     protected:
 #endif
+        /** Index of the currently pointed selected atom. */
         size_t i_select;
+
+        /** Index of the currently pointed rejected atom. */
         size_t j_reject;
 };