diff --git a/lib/libZRCola/include/zrcola/common.h b/lib/libZRCola/include/zrcola/common.h
index 5d2af28..cce794d 100644
--- a/lib/libZRCola/include/zrcola/common.h
+++ b/lib/libZRCola/include/zrcola/common.h
@@ -80,7 +80,7 @@ namespace ZRCola {
 
 
         ///
-        /// Compares two elements
+        /// Compares two elements (for searching)
         ///
         /// \param[in] a  Pointer to first element
         /// \param[in] b  Pointer to second element
@@ -93,6 +93,20 @@ namespace ZRCola {
         virtual int compare(_In_ const T &a, _In_ const T &b) const = 0;
 
 
+        ///
+        /// Compares two elements (for sorting)
+        ///
+        /// \param[in] a  Pointer to first element
+        /// \param[in] b  Pointer to second element
+        ///
+        /// \returns
+        /// - <0 when a <  b
+        /// - =0 when a == b
+        /// - >0 when a >  b
+        ///
+        virtual int compare_sort(_In_ const T &a, _In_ const T &b) const = 0;
+
+
         ///
         /// Search for the element in the index
         /// The elements matching \p el are located on the interval [\p start, \p end) in the index.
@@ -139,7 +153,7 @@ namespace ZRCola {
         static int __cdecl compare_s(void *p, const void *a, const void *b)
         {
             const index<T, T_idx> *t = (const index<T, T_idx>*)p;
-            return t->compare(t->host[*(const T_idx*)a], t->host[*(const T_idx*)b]);
+            return t->compare_sort(t->host[*(const T_idx*)a], t->host[*(const T_idx*)b]);
         }
     };
 
diff --git a/lib/libZRCola/include/zrcola/translate.h b/lib/libZRCola/include/zrcola/translate.h
index 534762a..dcf2242 100644
--- a/lib/libZRCola/include/zrcola/translate.h
+++ b/lib/libZRCola/include/zrcola/translate.h
@@ -92,7 +92,7 @@ namespace ZRCola {
             indexComp(_In_ std::vector<unsigned __int16> &h) : index<unsigned __int16, unsigned __int32>(h) {}
 
             ///
-            /// Compares two transformations by string
+            /// Compares two transformations by string (for searching)
             ///
             /// \param[in] a  Pointer to key sequence
             /// \param[in] b  Pointer to second key sequence
@@ -113,6 +113,32 @@ namespace ZRCola {
 
                 return 0;
             }
+
+            ///
+            /// Compares two transformations by string (for sorting)
+            ///
+            /// \param[in] a  Pointer to first element
+            /// \param[in] b  Pointer to second element
+            ///
+            /// \returns
+            /// - <0 when a <  b
+            /// - =0 when a == b
+            /// - >0 when a >  b
+            ///
+            virtual int compare_sort(_In_ const unsigned __int16 &a, _In_ const unsigned __int16 &b) const
+            {
+                const translation
+                    &trans_a = (const translation&)a,
+                    &trans_b = (const translation&)b;
+
+                int r = translation::CompareString(trans_a.str, trans_a.str_len, trans_b.str, trans_b.str_len);
+                if (r != 0) return r;
+
+                     if (trans_a.chr < trans_b.chr) return -1;
+                else if (trans_a.chr > trans_b.chr) return +1;
+
+                return 0;
+            }
         } idxComp;      ///< Composition index
 
 
@@ -130,7 +156,7 @@ namespace ZRCola {
             indexDecomp(_In_ std::vector<unsigned __int16> &h) : index<unsigned __int16, unsigned __int32>(h) {}
 
             ///
-            /// Compares two transformations by string
+            /// Compares two transformations by character (for searching)
             ///
             /// \param[in] a  Pointer to key sequence
             /// \param[in] b  Pointer to second key sequence
@@ -151,6 +177,32 @@ namespace ZRCola {
 
                 return 0;
             }
+
+            ///
+            /// Compares two transformations by character (for sorting)
+            ///
+            /// \param[in] a  Pointer to first element
+            /// \param[in] b  Pointer to second element
+            ///
+            /// \returns
+            /// - <0 when a <  b
+            /// - =0 when a == b
+            /// - >0 when a >  b
+            ///
+            virtual int compare_sort(_In_ const unsigned __int16 &a, _In_ const unsigned __int16 &b) const
+            {
+                const translation
+                    &trans_a = (const translation&)a,
+                    &trans_b = (const translation&)b;
+
+                     if (trans_a.chr < trans_b.chr) return -1;
+                else if (trans_a.chr > trans_b.chr) return +1;
+
+                int r = translation::CompareString(trans_a.str, trans_a.str_len, trans_b.str, trans_b.str_len);
+                if (r != 0) return r;
+
+                return 0;
+            }
         } idxDecomp;    ///< Decomposition index
 
 
diff --git a/lib/libZRColaUI/include/zrcolaui/keyboard.h b/lib/libZRColaUI/include/zrcolaui/keyboard.h
index 8ebfd74..865a8cb 100644
--- a/lib/libZRColaUI/include/zrcolaui/keyboard.h
+++ b/lib/libZRColaUI/include/zrcolaui/keyboard.h
@@ -100,7 +100,7 @@ namespace ZRCola {
             indexChr(_In_ std::vector<unsigned __int16> &h) : index<unsigned __int16, unsigned __int32>(h) {}
 
             ///
-            /// Compares two key sequences by character
+            /// Compares two key sequences by character (for searching)
             ///
             /// \param[in] a  Pointer to key sequence
             /// \param[in] b  Pointer to second key sequence
@@ -121,6 +121,32 @@ namespace ZRCola {
 
                 return 0;
             }
+
+            ///
+            /// Compares two key sequences by character (for sorting)
+            ///
+            /// \param[in] a  Pointer to key sequence
+            /// \param[in] b  Pointer to second key sequence
+            ///
+            /// \returns
+            /// - <0 when a <  b
+            /// - =0 when a == b
+            /// - >0 when a >  b
+            ///
+            virtual int compare_sort(_In_ const unsigned __int16 &a, _In_ const unsigned __int16 &b) const
+            {
+                const keyseq
+                    &ks_a = (const keyseq&)a,
+                    &ks_b = (const keyseq&)b;
+
+                     if (ks_a.chr < ks_b.chr) return -1;
+                else if (ks_a.chr > ks_b.chr) return +1;
+
+                int r = keyseq::CompareSequence(ks_a.seq, ks_a.seq_len, ks_b.seq, ks_b.seq_len);
+                if (r != 0) return r;
+
+                return 0;
+            }
         } idxChr;   ///< Character index
 
 
@@ -138,7 +164,7 @@ namespace ZRCola {
             indexKey(_In_ std::vector<unsigned __int16> &h) : index<unsigned __int16, unsigned __int32>(h) {}
 
             ///
-            /// Compares two key sequences by key
+            /// Compares two key sequences by key (for searching)
             ///
             /// \param[in] a  Pointer to key sequence
             /// \param[in] b  Pointer to second key sequence
@@ -159,6 +185,32 @@ namespace ZRCola {
 
                 return 0;
             }
+
+            ///
+            /// Compares two key sequences by key (for sorting)
+            ///
+            /// \param[in] a  Pointer to key sequence
+            /// \param[in] b  Pointer to second key sequence
+            ///
+            /// \returns
+            /// - <0 when a <  b
+            /// - =0 when a == b
+            /// - >0 when a >  b
+            ///
+            virtual int compare_sort(_In_ const unsigned __int16 &a, _In_ const unsigned __int16 &b) const
+            {
+                const keyseq
+                    &ks_a = (const keyseq&)a,
+                    &ks_b = (const keyseq&)b;
+
+                int r = keyseq::CompareSequence(ks_a.seq, ks_a.seq_len, ks_b.seq, ks_b.seq_len);
+                if (r != 0) return r;
+
+                     if (ks_a.chr < ks_b.chr) return -1;
+                else if (ks_a.chr > ks_b.chr) return +1;
+
+                return 0;
+            }
         } idxKey;   ///< Key index
 
         std::vector<unsigned __int16> data;     ///< Key sequences data