diff --git a/libasd/tag.hpp b/libasd/tag.hpp
index dbbf89e..b81839a 100644
--- a/libasd/tag.hpp
+++ b/libasd/tag.hpp
@@ -14,5 +14,13 @@ struct version : std::integral_constant<std::size_t, N>{};
 template<std::size_t N> using ch  = channel<N>;
 template<std::size_t N> using ver = version<N>;
 
+#if __cplusplus >= 201703L
+constexpr inline auto ch1 = channel<1>;
+constexpr inline auto ch2 = channel<2>;
+constexpr inline auto v0  = version<0>;
+constexpr inline auto v1  = version<1>;
+constexpr inline auto v2  = version<2>;
+#endif
+
 } // asd
 #endif//LIBASD_CHANNEL_TAG_H