diff --git a/loterre-resolvers/v1/9SD/identify.ini b/loterre-resolvers/v1/9SD/identify.ini
index 26982a1..7c616d0 100644
--- a/loterre-resolvers/v1/9SD/identify.ini
+++ b/loterre-resolvers/v1/9SD/identify.ini
@@ -48,7 +48,7 @@
 
 [expand/assign]
 path = value
-value = get('value').lowerCase()
+value = get('value').deburr().replace(/[`~!@#$%^&*()_|+\-=?;:'",.<>\{\}\[\]\\\/\s]/g, '').lowerCase()
 
 [expand/combine]
 path = value
diff --git a/loterre-resolvers/v1/combine.ini b/loterre-resolvers/v1/combine.ini
index d6cd7b1..371a8ca 100644
--- a/loterre-resolvers/v1/combine.ini
+++ b/loterre-resolvers/v1/combine.ini
@@ -46,7 +46,7 @@
 value = fix(_.get(self, 'skos$prefLabel'), _.get(self, 'skos$altLabel'), _.get(self, 'skos$hiddenLabel')). \
         flatten().\
 		filter(o => _.has(o, '$t')).\
-		map(o =>_.lowerCase(_.trim((o.$t)))).\
+		map(o => _.deburr(String(o.$t).replace(/[`~!@#$%^&*()_|+\-=?;:'",.<>\{\}\[\]\\\/\s]/g, '').toLowerCase())).\
 		reduce((accumulator, value, key, collection) => (_.indexOf(collection, value) >= 0 ? accumulator.concat(value) : accumulator), [])