diff --git a/lib/msun/man/erf.3 b/lib/msun/man/erf.3
--- a/lib/msun/man/erf.3
+++ b/lib/msun/man/erf.3
@@ -25,7 +25,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd July 13, 2014
+.Dd June 23, 2024
 .Dt ERF 3
 .Os
 .Sh NAME
@@ -86,6 +86,17 @@
 from 1.0.
 .Sh SEE ALSO
 .Xr math 3
+.Sh STANDARDS
+The
+.Fn erf ,
+.Fn erff ,
+.Fn erfl ,
+.Fn erfc ,
+.Fn erfcf
+and
+.Fn erfcl
+functions conform to
+.St -isoC-99 .
 .Sh HISTORY
 The
 .Fn erf