diff -r c15dc8762bdb -r bf2c546f49d1 src/lib/ASN1ContentHandler.h
--- a/src/lib/ASN1ContentHandler.h	Sat Jul 17 20:38:03 2021 +0200
+++ b/src/lib/ASN1ContentHandler.h	Sun Jul 18 12:37:40 2021 +0200
@@ -291,6 +291,15 @@
 	// OID-IRI
 	// Relative OID-IRI
 
+	/**
+	 * Specific value that was not parsed.
+	 * May be processed in a generic way (as binary data or ASCII or UTF-8 string, when possible)
+	 * or according to given application, context or private specification.
+	 * 
+	 * @param value original raw data
+	 */
+	virtual void writeSpecific(const Header& header, std::string value) = 0;
+
 };
 
 class ASN1ContentHandlerProxy : public ASN1ContentHandler {
@@ -350,6 +359,10 @@
 		handlers.forward(&ASN1ContentHandler::writeDateTime, header, value);
 	}
 
+	void writeSpecific(const Header& header, std::string value) override {
+		handlers.forward(&ASN1ContentHandler::writeSpecific, header, value);
+	}
+
 };