diff --git a/registries/ltru.rnc b/registries/ltru.rnc
index 9f5f76b..ead4371 100644
--- a/registries/ltru.rnc
+++ b/registries/ltru.rnc
@@ -46,7 +46,7 @@ redundants = redundant*
 
 redundant = element redundant {tag & common}
 
-common = added & descriptions & comments? & deprecated? & preferred-value?
+common = added & descriptions & multiple-comments? & deprecated? & preferred-value?
 
 added = element added {xsd:date}
 
@@ -66,6 +66,8 @@ macrolanguage = element macrolanguage {text}
 
 deprecated = element deprecated {xsd:date}
 
+multiple-comments = comments+
+
 comments = element comments {text}
 
 preferred-value = element preferred-value {text}