diff --git a/include/xo/unit/dim_util.hpp b/include/xo/unit/dim_util.hpp
index ad2f349..0f84b95 100644
--- a/include/xo/unit/dim_util.hpp
+++ b/include/xo/unit/dim_util.hpp
@@ -21,7 +21,7 @@ namespace xo {
              *        (1usd + 1eur) is well-defined,  but (1sec + 1m) is not.
              **/
             currency,
-            /** a screen price. dimensionless **/
+            /** a screen price **/
             price,
         };
 
diff --git a/include/xo/unit/numeric_concept.hpp b/include/xo/unit/numeric_concept.hpp
index 720099a..f1d32f5 100644
--- a/include/xo/unit/numeric_concept.hpp
+++ b/include/xo/unit/numeric_concept.hpp
@@ -11,13 +11,9 @@ namespace xo {
          *
          *  Intended to include at least:
          *  - built-in integral and floating-point types
-         *  - boost::rational<U>
-         *  - std::complex<U>
+         *  - xo::raio<U>
          *  - xo::unit::quantity<U,R>
          *
-         *  This implies we don't require T to be totally ordered,
-         *  and don't require (<,<=,>=,>) operators.
-         *
          *  Intend numeric_concept to apply to types suitable for
          *  xo::unit::quantity::repr_type.
          **/