diff --git a/mcc/mcc_defaults.h b/mcc/mcc_defaults.h
index 0893c60..ce2158e 100644
--- a/mcc/mcc_defaults.h
+++ b/mcc/mcc_defaults.h
@@ -504,9 +504,12 @@ static_assert(mcc_celestial_point_c<MccCelestialPoint>, "");
 static_assert(mcc_telemetry_data_c<MccTelemetryData>, "");
 
 
+
 /*                          DEFAULT SERIALIZER/DESERIALIZER FOR COORDINATE-RELATED CLASSES                          */
 
 
+static constexpr std::string_view MccCoordinateDefaultDelimiter{","};
+
 // base class
 class MccCoordinateDeserializer
 {
@@ -536,7 +539,7 @@ public:
     }
 
 protected:
-    std::string _delimiter{","};
+    std::string _delimiter{MccCoordinateDefaultDelimiter};
 
     template <traits::mcc_input_char_range IR>
     std::vector<std::string_view> splitToElements(IR&& bytes)
@@ -629,7 +632,7 @@ protected:
     SerializedCoordFormat _currentFormat{CFMT_DEGREES};
     SexagesimalCoordPrec _currentPrec{.hour_prec = 2, .deg_prec = 1};
 
-    std::string _delimiter{","};
+    std::string _delimiter{MccCoordinateDefaultDelimiter};
 
     template <mcc_celestial_point_c T, traits::mcc_output_char_range OR>
     void serializePairKindTimePoint(const T& value, OR& bytes)
@@ -777,10 +780,131 @@ public:
 
 class MccEqtHrzCoordsSerializer : public MccCoordinateSerializer
 {
+    template <mcc_eqt_hrz_coord_c T, traits::mcc_output_char_range OR>
+    void operator()(const T& value, OR& bytes)
+    {
+        // output format: RA, DEC, HA, AZ, ZD, ALT, X, Y, pair-kind, time-point
+        // in the case of sexagesimal output X,Y coordinates will be interpretated
+        // according to value.pair_kind field
+
+        if (_currentFormat == SerializedCoordFormat::CFMT_DEGREES) {
+            toDegrees(bytes, value.RA_APP, value.DEC_APP, value.HA, value.AZ, value.ZD, value.ALT, value.X, value.Y);
+        } else if (_currentFormat == SerializedCoordFormat::CFMT_SGM) {
+            toSexagesimalHour(bytes, value.RA_APP);
+            std::format_to(std::back_inserter(bytes), "{}", _delimiter);
+
+            toSexagesimalDeg(bytes, value.DEC_APP);
+            std::format_to(std::back_inserter(bytes), "{}", _delimiter);
+
+            toSexagesimalHour(bytes, value.HA);
+            std::format_to(std::back_inserter(bytes), "{}", _delimiter);
+
+            toSexagesimalDeg(bytes, value.AZ, value.ZD, value.ALT);
+            std::format_to(std::back_inserter(bytes), "{}", _delimiter);
+
+            switch (value.pair_kind) {
+                case MccCoordPairKind::COORDS_KIND_RADEC_ICRS:
+                case MccCoordPairKind::COORDS_KIND_RADEC_APP:
+                case MccCoordPairKind::COORDS_KIND_HADEC_APP:
+                    toSexagesimalHour(bytes, value.X);
+                    break;
+                default:
+                    toSexagesimalDeg(bytes, value.X);
+            }
+
+            std::format_to(std::back_inserter(bytes), "{}", _delimiter);
+            toSexagesimalDeg(bytes, value.Y);
+        } else {
+            // !!!!!
+        }
+
+        std::format_to(std::back_inserter(bytes), "{}", _delimiter);
+
+        serializePairKindTimePoint(value, bytes);
+    }
 };
 
 class MccEqtHrzCoordsDeserializer : public MccCoordinateDeserializer
 {
+    template <traits::mcc_input_char_range IR, mcc_eqt_hrz_coord_c T>
+    std::error_code operator()(IR&& bytes, T& value)
+    {
+        auto els = splitToElements(std::forward<IR>(bytes));
+    }
 };
 
+
+
+/**/
+
+static constexpr char MccCoordinateXFmt = 'x';
+static constexpr char MccCoordinateYFmt = 'y';
+static constexpr char MccCoordinateRA_ICRSFmt = 'R';
+static constexpr char MccCoordinateDEC_ICRSFmt = 'D';
+static constexpr char MccCoordinateRA_APPFmt = 'r';
+static constexpr char MccCoordinateDEC_APPFmt = 'd';
+static constexpr char MccCoordinateHAFmt = 'h';
+static constexpr char MccCoordinateAZFmt = 'a';
+static constexpr char MccCoordinateZDFmt = 'z';
+static constexpr char MccCoordinateALTFmt = 'A';
+static constexpr char MccCoordinateTMFmt = 't';  // time point
+static constexpr char MccCoordinatePKFmt = 'p';  // pair kind
+
+
 }  // namespace mcc
+
+
+template <mcc::mcc_celestial_point_c T>
+struct std::formatter<T, char> {
+    std::vector<char> fmt_order;
+
+    template <typename ParseContext>
+    constexpr ParseContext::iterator parse(ParseContext& ctx)
+    {
+        bool do_fmt = false;
+
+        for (auto it = ctx.begin(); it != ctx.end(); ++it) {
+            if (*it == '%' && !do_fmt) {
+                do_fmt = true;
+                continue;
+            } else {
+                throw std::format_error("Invalid format argument for celestial point");
+            }
+
+            switch (*it) {
+                case mcc::MccCoordinateXFmt:
+                case mcc::MccCoordinateYFmt:
+                case mcc::MccCoordinateRA_ICRSFmt:
+                case mcc::MccCoordinateDEC_ICRSFmt:
+                case mcc::MccCoordinateRA_APPFmt:
+                case mcc::MccCoordinateDEC_APPFmt:
+                case mcc::MccCoordinateHAFmt:
+                case mcc::MccCoordinateAZFmt:
+                case mcc::MccCoordinateZDFmt:
+                case mcc::MccCoordinateALTFmt:
+                case mcc::MccCoordinateTMFmt:
+                case mcc::MccCoordinatePKFmt:
+                    fmt_order.push_back(*it);
+                    do_fmt = false;
+                    break;
+                default:
+                    throw std::format_error("Invalid format argument for celestial point");
+            }
+        }
+    }
+
+    template <typename FmtContext>
+    FmtContext::iterator format(mcc::mcc_celestial_point_c auto cp, FmtContext& ctx) const
+    {
+        std::ostringstream out;
+
+        if (fmt_order.empty()) {
+            return ctx.out();
+        }
+
+        for (auto& el : fmt_order) {
+        }
+
+        return std::ranges::copy(std::move(out).str(), ctx.out()).out;
+    }
+};
diff --git a/mcc/mcc_netserver_proto.h b/mcc/mcc_netserver_proto.h
index b35a610..a6c4203 100644
--- a/mcc/mcc_netserver_proto.h
+++ b/mcc/mcc_netserver_proto.h
@@ -682,7 +682,7 @@ protected:
                 (*this)(value.count(), bytes);
             } else if constexpr (mcc_eqt_hrz_coord_c<T>) {
                 // output format: RA, DEC, HA, AZ, ZD, ALT, X, Y, pair-kind, time-point
-                // in the case of sexagesimal output X,Y coordinates will be interprateted
+                // in the case of sexagesimal output X,Y coordinates will be interpretated
                 // according to value.pair_kind field
                 if (_currentCoordFormat == MccNetMessageCoordFormat::CFMT_DEGREES) {
                     std::format_to(std::back_inserter(bytes), "{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}",