Starting in Strategy 9.3.1, additional logging is available for Distribution Services. The "DS Request Details" trace is useful when trying to determine the request details for a particular Distribution Services subscription. It can be found in the Strategy Diagnostics and Performance Logging tool as shown below:

Note: This log is not enabled by default. An existing or new "File Log" destination must be selected for this logging to be used.
When a subscription runs on a schedule or the "Send Now" feature is utilized, a subsequent job will be created for Distribution Services. This logging will display details about subscriptions that were triggered and the subscription recipients. The following entries are seen in the log when a subscription is triggered:
2013-11-30 19:51:51.055-05:00 NCSRequest::CreateCommandForExecution() mPhaseIndex = 0 bIsExpandedDRLGroup = false. <Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) > 2013-11-30 19:51:51.149-05:00 NCSRequest::CreateCommandForExecution() ContactType = 4 bIsExpandedDRLGroup = false lIsExpandedSubInstance = false mPhaseIndex = 0. <Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) > 2013-11-30 19:51:51.227-05:00 NCSRequest::CreateCommandForExecution() bToExpandSegmentBursting = false. <Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) > 2013-11-30 19:51:51.305-05:00 NCSRequest::CreateCommandForExecution() lDeliveryType = 1.<Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) > 2013-11-30 19:51:51.383-05:00 NCSRequest::CreateCommandForExecution() lbIsCacheUpdateForMobile = false.<Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) > 2013-11-30 19:51:51.398-05:00 NCSRequest::CreateCommandForExecution() bReportIsReadyAndConvertItToDocument = false.<Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) > 2013-11-30 19:51:51.429-05:00 NCSRequest::CreateCommandForExecution() lIsNormal = 1 bIsUnExpandedDRL = false. <Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) > 2013-11-30 19:51:51.476-05:00 NCSRequest::CreateCommandForExecution() lSubDataType = 3 bIsIPad = false bIsIPhone = false bConvertByReportDef = false.<Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) > 2013-11-30 19:51:51.507-05:00 NCSRequest::CreateCommandForExecution() aPromptAnswerXML = .<Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) > 2013-11-30 19:51:51.523-05:00 NCSRequest::CreateCommandForExecution() aViewSettingsXML = <vss resf="46268576"><vpr><gdp/><gpp/></vpr></vss>.<Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) > 2013-11-30 19:51:51.539-05:00 NCSRequest::CreateCommandForExecution() lChildSubscriptionTransformationSettings = EndDelimiter***BeginDelimiter++++***FileFormat++++4***export_settings++++<extendable_parameter><export_options ef="4" vm="1"><export_mode>1</export_mode></export_options></extendable_parameter>***IncludeData++++1***Subject++++Customer Income Analysis***fileName++++Customer Income Analysis***SendToHistory++++0***ReuseHL++++0***IncludeLink++++0***zip++++0***ProtectZipFile++++0***ContactCollectionMode++++0***stid++++0***expiration_date++++ ***.<Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) > 2013-11-30 19:51:51.554-05:00 NCSRequest::CreateCommandForExecution() aExecuteFlags = 0x5B2.<Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) > 2013-11-30 19:51:51.585-05:00 NCSRequest::CreateCommandForExecution() aReportActions = 0xE300003F aExecuteFlags = 0x5B2 aPromptAnswerXML = .<Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) >