diff --git a/config.md b/config.md
index 46937051b..7d95d09b6 100644
--- a/config.md
+++ b/config.md
@@ -460,7 +460,6 @@ Instead they MUST ignore unknown properties.
 ## Valid values
 
 Runtimes that are reading or processing this configuration file MUST generate an error when invalid or unsupported values are encountered.
-Unless support for a valid value is explicitly required, runtimes MAY choose which subset of the valid values it will support.
 
 ## Configuration Schema Example