diff --git a/include/xo/unit/basis_unit2.hpp b/include/xo/unit/basis_unit2.hpp
index 5d9ac775..06f81f4c 100644
--- a/include/xo/unit/basis_unit2.hpp
+++ b/include/xo/unit/basis_unit2.hpp
@@ -3,168 +3,13 @@
 #pragma once
 
 #include "native_unit.hpp"
+#include "basis_unit_abbrev.hpp"
 #include "xo/ratio/ratio.hpp"
 #include <algorithm>
 #include <vector>
 
 namespace xo {
     namespace qty {
-        using basis_unit2_abbrev_type = flatstring<16>;
-
-        using scalefactor_ratio_type = xo::ratio::ratio<std::int64_t>;
-
-        namespace abbrev {
-            // ----- units for dim::mass -----
-
-            static
-            constexpr basis_unit2_abbrev_type
-            mass_unit2_abbrev(const scalefactor_ratio_type & scalefactor)
-            {
-                if (scalefactor.num() == 1) {
-                    switch (scalefactor.den()) {
-                    case 1:
-                        return basis_unit2_abbrev_type::from_chars("g");
-                    case 1000:
-                        return basis_unit2_abbrev_type::from_chars("mg");
-                    case 1000000:
-                        return basis_unit2_abbrev_type::from_chars("ug");
-                    case 1000000000:
-                        return basis_unit2_abbrev_type::from_chars("ng");
-                    }
-                }
-
-                if (scalefactor.den() == 1) {
-                    switch (scalefactor.num()) {
-                    case 1000:
-                        return basis_unit2_abbrev_type::from_chars("kg");
-                    case 1000000:
-                        return basis_unit2_abbrev_type::from_chars("t");
-                    case 1000000000:
-                        return basis_unit2_abbrev_type::from_chars("kt");
-                    }
-                }
-
-                /* e.g. unit of '1000 grams' will have abbrev '1000g' in absence
-                 *      of a specialization for scaled_native_unit_abbrev
-                 */
-                return (basis_unit2_abbrev_type::from_flatstring
-                        (flatstring_concat
-                         (scalefactor.to_str<basis_unit2_abbrev_type::fixed_capacity>(),
-                          native_unit2_v[static_cast<std::uint32_t>(dim::mass)].abbrev_str())));
-            }
-
-            // ----- units for dim::distance -----
-
-            static
-            constexpr basis_unit2_abbrev_type
-            distance_unit2_abbrev(const scalefactor_ratio_type & scalefactor)
-            {
-                if (scalefactor.num() == 1) {
-                    switch (scalefactor.den()) {
-                    case 1:
-                        return basis_unit2_abbrev_type::from_chars("m");
-                    case 1000:
-                        return basis_unit2_abbrev_type::from_chars("mm");
-                    case 1000000:
-                        return basis_unit2_abbrev_type::from_chars("um");
-                    case 1000000000:
-                        return basis_unit2_abbrev_type::from_chars("nm");
-                    }
-                }
-
-                if (scalefactor.den() == 1) {
-                    switch (scalefactor.num()) {
-                    case 1000:
-                        return basis_unit2_abbrev_type::from_chars("km");
-                    case 1000000:
-                        return basis_unit2_abbrev_type::from_chars("Mm");
-                    case 1000000000:
-                        return basis_unit2_abbrev_type::from_chars("Gm");
-                    }
-                }
-
-                /* e.g. unit of '1000 grams' will have abbrev '1000g' in absence
-                 *      of a specialization for scaled_native_unit_abbrev
-                 */
-                return (basis_unit2_abbrev_type::from_flatstring
-                        (flatstring_concat
-                         (scalefactor.to_str<basis_unit2_abbrev_type::fixed_capacity>(),
-                          native_unit2_v[static_cast<std::uint32_t>(dim::mass)].abbrev_str())));
-            }
-
-            // ----- units for dim::time -----
-
-            static
-            constexpr basis_unit2_abbrev_type
-            time_unit2_abbrev(const scalefactor_ratio_type & scalefactor)
-            {
-                if (scalefactor.num() == 1) {
-                    switch (scalefactor.den()) {
-                    case 1:
-                        return basis_unit2_abbrev_type::from_chars("s");
-                    case 1000:
-                        return basis_unit2_abbrev_type::from_chars("ms");
-                    case 1000000:
-                        return basis_unit2_abbrev_type::from_chars("us");
-                    case 1000000000:
-                        return basis_unit2_abbrev_type::from_chars("ns");
-                    }
-                }
-
-                if (scalefactor.den() == 1) {
-                    switch (scalefactor.num()) {
-                    case 60:
-                        return basis_unit2_abbrev_type::from_chars("min");
-                    case 3600:
-                        return basis_unit2_abbrev_type::from_chars("hr");
-                    case 24*3600:
-                        return basis_unit2_abbrev_type::from_chars("dy");
-                    case 7*24*3600:
-                        return basis_unit2_abbrev_type::from_chars("wk");
-                    case 30*24*3600:
-                        return basis_unit2_abbrev_type::from_chars("mo");
-                    case 250*24*3600:
-                        return basis_unit2_abbrev_type::from_chars("yr250");
-                    case 360*24*3600:
-                        return basis_unit2_abbrev_type::from_chars("yr360");
-                    case 365*24*3600:
-                        return basis_unit2_abbrev_type::from_chars("yr365");
-                    }
-                }
-
-                /* e.g. unit of '1000 grams' will have abbrev '1000g' in absence
-                 *      of a specialization for scaled_native_unit_abbrev
-                 */
-                return (basis_unit2_abbrev_type::from_flatstring
-                        (flatstring_concat
-                         (scalefactor.to_str<basis_unit2_abbrev_type::fixed_capacity>(),
-                          native_unit2_v[static_cast<std::uint32_t>(dim::mass)].abbrev_str())));
-            }
-
-            static
-            constexpr basis_unit2_abbrev_type
-            basis_unit2_abbrev(dim native_dim,
-                               const scalefactor_ratio_type & scalefactor)
-            {
-                switch(native_dim) {
-                case dim::mass:
-                    return mass_unit2_abbrev(scalefactor);
-                case dim::distance:
-                    return distance_unit2_abbrev(scalefactor);
-                case dim::time:
-                    return time_unit2_abbrev(scalefactor);
-                }
-
-                /* e.g. unit of '1000 grams' will have abbrev '1000g' in absence
-                 *      of a specialization for scaled_native_unit_abbrev
-                 */
-                return (basis_unit2_abbrev_type::from_flatstring
-                        (flatstring_concat
-                         (scalefactor.to_str<basis_unit2_abbrev_type::fixed_capacity>(),
-                          native_unit2_v[static_cast<std::uint32_t>(native_dim)].abbrev_str())));
-            }
-        }; /*abbrev*/
-
         /** @class basis_unit2
          *  @brief A dimensionless multiple of a single natively-specified basis dimension
          *
diff --git a/include/xo/unit/basis_unit_abbrev.hpp b/include/xo/unit/basis_unit_abbrev.hpp
new file mode 100644
index 00000000..eee7dfda
--- /dev/null
+++ b/include/xo/unit/basis_unit_abbrev.hpp
@@ -0,0 +1,205 @@
+/** @file basis_unit_abbrev.hpp
+ *
+ *  Author: Roland Conybeare
+ **/
+
+#pragma once
+
+#include "native_unit.hpp"
+#include "xo/ratio/ratio.hpp"
+//#include <cstdint>
+
+namespace xo {
+    namespace qty {
+        using basis_unit2_abbrev_type = flatstring<16>;
+        using scalefactor_ratio_type = xo::ratio::ratio<std::int64_t>;
+
+        namespace abbrev {
+            static
+            constexpr basis_unit2_abbrev_type
+            fallback_unit_abbrev(const scalefactor_ratio_type & scalefactor,
+                                 dim native_dim)
+            {
+                /* e.g. unit of '1000 grams' will have abbrev '1000g' in absence
+                 *      of a specialization for scaled_native_unit_abbrev
+                 */
+                return (basis_unit2_abbrev_type::from_flatstring
+                        (flatstring_concat
+                         (scalefactor.to_str<basis_unit2_abbrev_type::fixed_capacity>(),
+                          native_unit2_v[static_cast<std::uint32_t>(native_dim)].abbrev_str())));
+            }
+
+            // ----- units for dim::mass -----
+
+            static
+            constexpr basis_unit2_abbrev_type
+            mass_unit2_abbrev(const scalefactor_ratio_type & scalefactor)
+            {
+                if (scalefactor.num() == 1) {
+                    switch (scalefactor.den()) {
+                    case 1:
+                        return basis_unit2_abbrev_type::from_chars("g");
+                    case 1000:
+                        return basis_unit2_abbrev_type::from_chars("mg");
+                    case 1000000:
+                        return basis_unit2_abbrev_type::from_chars("ug");
+                    case 1000000000:
+                        return basis_unit2_abbrev_type::from_chars("ng");
+                    }
+                }
+
+                if (scalefactor.den() == 1) {
+                    switch (scalefactor.num()) {
+                    case 1000:
+                        return basis_unit2_abbrev_type::from_chars("kg");
+                    case 1000000:
+                        return basis_unit2_abbrev_type::from_chars("t");
+                    case 1000000000:
+                        return basis_unit2_abbrev_type::from_chars("kt");
+                    }
+                }
+
+                return fallback_unit_abbrev(scalefactor, dim::mass);
+            }
+
+            // ----- units for dim::distance -----
+
+            static
+            constexpr basis_unit2_abbrev_type
+            distance_unit2_abbrev(const scalefactor_ratio_type & scalefactor)
+            {
+                if (scalefactor.num() == 1) {
+                    switch (scalefactor.den()) {
+                    case 1:
+                        return basis_unit2_abbrev_type::from_chars("m");
+                    case 1000:
+                        return basis_unit2_abbrev_type::from_chars("mm");
+                    case 1000000:
+                        return basis_unit2_abbrev_type::from_chars("um");
+                    case 1000000000:
+                        return basis_unit2_abbrev_type::from_chars("nm");
+                    }
+                }
+
+                if (scalefactor.den() == 1) {
+                    switch (scalefactor.num()) {
+                    case 1000:
+                        return basis_unit2_abbrev_type::from_chars("km");
+                    case 1000000:
+                        return basis_unit2_abbrev_type::from_chars("Mm");
+                    case 1000000000:
+                        return basis_unit2_abbrev_type::from_chars("Gm");
+                    }
+                }
+
+                return fallback_unit_abbrev(scalefactor, dim::distance);
+            }
+
+            // ----- units for dim::time -----
+
+            static
+            constexpr basis_unit2_abbrev_type
+            time_unit2_abbrev(const scalefactor_ratio_type & scalefactor)
+            {
+                if (scalefactor.num() == 1) {
+                    switch (scalefactor.den()) {
+                    case 1:
+                        return basis_unit2_abbrev_type::from_chars("s");
+                    case 1000:
+                        return basis_unit2_abbrev_type::from_chars("ms");
+                    case 1000000:
+                        return basis_unit2_abbrev_type::from_chars("us");
+                    case 1000000000:
+                        return basis_unit2_abbrev_type::from_chars("ns");
+                    }
+                }
+
+                if (scalefactor.den() == 1) {
+                    switch (scalefactor.num()) {
+                    case 60:
+                        return basis_unit2_abbrev_type::from_chars("min");
+                    case 3600:
+                        return basis_unit2_abbrev_type::from_chars("hr");
+                    case 24*3600:
+                        return basis_unit2_abbrev_type::from_chars("dy");
+                    case 7*24*3600:
+                        return basis_unit2_abbrev_type::from_chars("wk");
+                    case 30*24*3600:
+                        return basis_unit2_abbrev_type::from_chars("mo");
+                    case 250*24*3600:
+                        return basis_unit2_abbrev_type::from_chars("yr250");
+                    case 360*24*3600:
+                        return basis_unit2_abbrev_type::from_chars("yr360");
+                    case 365*24*3600:
+                        return basis_unit2_abbrev_type::from_chars("yr365");
+                    }
+                }
+
+                return fallback_unit_abbrev(scalefactor, dim::time);
+            }
+
+            // ----- units for dim::currency -----
+
+            static constexpr basis_unit2_abbrev_type
+            currency_unit2_abbrev(const scalefactor_ratio_type & scalefactor)
+            {
+                if (scalefactor.num() == 1) {
+                    switch(scalefactor.den()) {
+                    case 1:
+                        return basis_unit2_abbrev_type::from_chars("ccy");
+                    }
+                }
+
+                return fallback_unit_abbrev(scalefactor, dim::currency);
+            }
+
+            // ----- units for dim::price -----
+
+            static constexpr basis_unit2_abbrev_type
+            price_unit2_abbrev(const scalefactor_ratio_type & scalefactor)
+            {
+                if (scalefactor.num() == 1) {
+                    switch(scalefactor.den()) {
+                    case 1:
+                        return basis_unit2_abbrev_type::from_chars("ccy");
+                    }
+                }
+
+                return fallback_unit_abbrev(scalefactor, dim::price);
+            }
+
+            static
+            constexpr basis_unit2_abbrev_type
+            basis_unit2_abbrev(dim native_dim,
+                               const scalefactor_ratio_type & scalefactor)
+            {
+                switch(native_dim) {
+                case dim::mass:
+                    return mass_unit2_abbrev(scalefactor);
+                case dim::distance:
+                    return distance_unit2_abbrev(scalefactor);
+                case dim::time:
+                    return time_unit2_abbrev(scalefactor);
+                case dim::currency:
+                    return currency_unit2_abbrev(scalefactor);
+                case dim::price:
+                    return price_unit2_abbrev(scalefactor);
+                case dim::invalid:
+                case dim::n_dim:
+                    break;
+                }
+
+                /* e.g. unit of '1000 grams' will have abbrev '1000g' in absence
+                 *      of a specialization for scaled_native_unit_abbrev
+                 */
+                return (basis_unit2_abbrev_type::from_flatstring
+                        (flatstring_concat
+                         (scalefactor.to_str<basis_unit2_abbrev_type::fixed_capacity>(),
+                          native_unit2_v[static_cast<std::uint32_t>(native_dim)].abbrev_str())));
+            }
+        } /*namespace abbrev*/
+    } /*namespace qty*/
+} /*namespace xo*/
+
+
+/** end basis_unit_abbrev.hpp **/
diff --git a/include/xo/unit/native_unit.hpp b/include/xo/unit/native_unit.hpp
index 402a9e3d..ac003ef1 100644
--- a/include/xo/unit/native_unit.hpp
+++ b/include/xo/unit/native_unit.hpp
@@ -1,4 +1,4 @@
-/** @file dim_util2.hpp
+/** @file native_unit.hpp
  *
  *  Author: Roland Conybeare
  **/
@@ -12,17 +12,17 @@ namespace xo {
     namespace qty {
         using native_unit2_abbrev_type = flatstring<8>;
 
-        /** @class native_unit2
+        /** @class native_unit
          *
          *  @brief Represent a native (built-in) unit.
          *
-         *  A basis_unit2 is expressed as a multiple of a native_unit2
+         *  A basis_unit is expressed as a multiple of a native_unit
          *
          **/
         struct native_unit {
         public:
             constexpr native_unit(dim native_dim,
-                                   const native_unit2_abbrev_type & abbrev_str)
+                                  const native_unit2_abbrev_type & abbrev_str)
                 : native_dim_{native_dim},
                   abbrev_str_{abbrev_str}
                 {}
@@ -46,6 +46,4 @@ namespace xo {
     } /*namespace qty*/
 } /*namespace xo*/
 
-
-
-/** end dim_util2.hpp **/
+/** end native_unit.hpp **/