(PECL varnish >= 0.6)
VarnishLog::TAG_Debug
VarnishLog::TAG_Error
VarnishLog::TAG_CLI
VarnishLog::TAG_StatSess
VarnishLog::TAG_ReqEnd
VarnishLog::TAG_SessionOpen
VarnishLog::TAG_SessionClose
VarnishLog::TAG_BackendOpen
VarnishLog::TAG_BackendXID
VarnishLog::TAG_BackendReuse
VarnishLog::TAG_BackendClose
VarnishLog::TAG_HttpGarbage
VarnishLog::TAG_Backend
VarnishLog::TAG_Length
VarnishLog::TAG_FetchError
VarnishLog::TAG_RxRequest
VarnishLog::TAG_RxResponse
VarnishLog::TAG_RxStatus
VarnishLog::TAG_RxURL
VarnishLog::TAG_RxProtocol
VarnishLog::TAG_RxHeader
VarnishLog::TAG_TxRequest
VarnishLog::TAG_TxResponse
VarnishLog::TAG_TxStatus
VarnishLog::TAG_TxURL
VarnishLog::TAG_TxProtocol
VarnishLog::TAG_TxHeader
VarnishLog::TAG_ObjRequest
VarnishLog::TAG_ObjResponse
VarnishLog::TAG_ObjStatus
VarnishLog::TAG_ObjURL
VarnishLog::TAG_ObjProtocol
VarnishLog::TAG_ObjHeader
VarnishLog::TAG_LostHeader
VarnishLog::TAG_TTL
VarnishLog::TAG_Fetch_Body
VarnishLog::TAG_VCL_acl
VarnishLog::TAG_VCL_call
VarnishLog::TAG_VCL_trace
VarnishLog::TAG_VCL_return
VarnishLog::TAG_VCL_error
VarnishLog::TAG_ReqStart
VarnishLog::TAG_Hit
VarnishLog::TAG_HitPass
VarnishLog::TAG_ExpBan
VarnishLog::TAG_ExpKill
VarnishLog::TAG_WorkThread
VarnishLog::TAG_ESI_xmlerror
VarnishLog::TAG_Hash
VarnishLog::TAG_Backend_health
VarnishLog::TAG_VCL_Log
VarnishLog::TAG_Gzip