diff --git a/tlv.h b/tlv.h
index 613938e..52bf0f6 100644
--- a/tlv.h
+++ b/tlv.h
@@ -22,6 +22,80 @@
 
 #include "ddt.h"
 
+/* TLV types */
+#define TLV_MANAGEMENT					0x0001
+#define TLV_MANAGEMENT_ERROR_STATUS			0x0002
+#define TLV_ORGANIZATION_EXTENSION			0x0003
+#define TLV_REQUEST_UNICAST_TRANSMISSION		0x0004
+#define TLV_GRANT_UNICAST_TRANSMISSION			0x0005
+#define TLV_CANCEL_UNICAST_TRANSMISSION			0x0006
+#define TLV_ACKNOWLEDGE_CANCEL_UNICAST_TRANSMISSION	0x0007
+#define TLV_PATH_TRACE					0x0008
+#define TLV_ALTERNATE_TIME_OFFSET_INDICATOR		0x0009
+#define TLV_AUTHENTICATION				0x2000
+#define TLV_AUTHENTICATION_CHALLENGE			0x2001
+#define TLV_SECURITY_ASSOCIATION_UPDATE			0x2002
+#define TLV_CUM_FREQ_SCALE_FACTOR_OFFSET		0x2003
+
+enum management_action {
+	GET,
+	SET,
+	RESPONSE,
+	COMMAND,
+	ACKNOWLEDGE,
+};
+
+/* Clock management ID values */
+#define USER_DESCRIPTION				0x0002
+#define SAVE_IN_NON_VOLATILE_STORAGE			0x0003
+#define RESET_NON_VOLATILE_STORAGE			0x0004
+#define INITIALIZE					0x0005
+#define FAULT_LOG					0x0006
+#define FAULT_LOG_RESET					0x0007
+#define DEFAULT_DATA_SET				0x2000
+#define CURRENT_DATA_SET				0x2001
+#define PARENT_DATA_SET					0x2002
+#define TIME_PROPERTIES_DATA_SET			0x2003
+#define PRIORITY1					0x2005
+#define PRIORITY2					0x2006
+#define DOMAIN						0x2007
+#define SLAVE_ONLY					0x2008
+#define TIME						0x200F
+#define CLOCK_ACCURACY					0x2010
+#define UTC_PROPERTIES					0x2011
+#define TRACEABILITY_PROPERTIES				0x2012
+#define TIMESCALE_PROPERTIES				0x2013
+#define PATH_TRACE_LIST					0x2015
+#define PATH_TRACE_ENABLE				0x2016
+#define GRANDMASTER_CLUSTER_TABLE			0x2017
+#define ACCEPTABLE_MASTER_TABLE				0x201A
+#define ACCEPTABLE_MASTER_MAX_TABLE_SIZE		0x201C
+#define ALTERNATE_TIME_OFFSET_ENABLE			0x201E
+#define ALTERNATE_TIME_OFFSET_NAME			0x201F
+#define ALTERNATE_TIME_OFFSET_MAX_KEY			0x2020
+#define ALTERNATE_TIME_OFFSET_PROPERTIES		0x2021
+#define TRANSPARENT_CLOCK_DEFAULT_DATA_SET		0x4000
+#define PRIMARY_DOMAIN					0x4002
+
+/* Port management ID values */
+#define NULL_MANAGEMENT					0x0000
+#define CLOCK_DESCRIPTION				0x0001
+#define PORT_DATA_SET					0x2004
+#define LOG_ANNOUNCE_INTERVAL				0x2009
+#define ANNOUNCE_RECEIPT_TIMEOUT			0x200A
+#define LOG_SYNC_INTERVAL				0x200B
+#define VERSION_NUMBER					0x200C
+#define ENABLE_PORT					0x200D
+#define DISABLE_PORT					0x200E
+#define UNICAST_NEGOTIATION_ENABLE			0x2014
+#define UNICAST_MASTER_TABLE				0x2018
+#define UNICAST_MASTER_MAX_TABLE_SIZE			0x2019
+#define ACCEPTABLE_MASTER_TABLE_ENABLED			0x201B
+#define ALTERNATE_MASTER				0x201D
+#define TRANSPARENT_CLOCK_PORT_DATA_SET			0x4001
+#define DELAY_MECHANISM					0x6000
+#define LOG_MIN_PDELAY_REQ_INTERVAL			0x6001
+
 /**
  * Converts recognized value sub-fields into host byte order.
  * @param tlv Pointer to a Type Length Value field.