SQS and SNS resources

Messaging classes configure SQS queues, redrive behavior, queue policies, SNS topics, subscriptions, filters, and topic policies.

Source: mde/metamodels/psm/awspsm-messaging.emf.

`SqsQueue`

Represents sqs queue in the PSM vocabulary. It specializes AwsResource, S3NotificationDestination with the details needed for this modeling concern.

Direct supertypes: AwsResource, S3NotificationDestination. Inherited attributes and marker capabilities are documented in the shared kernel; this section lists every attribute declared by this class.

Declared attributes

Attribute	Type and multiplicity	What it captures and why it exists	Accepted values and example
`queueName`	`String` [1]	Stores the stable name/key/code used for queue name on the sqs queue. The field keeps the model explicit and reviewable during review and transformation instead of leaving the decision to an inferred default. Semantic validation: `FifoQueueNameSuffix` (fifo queue name suffix) in `mde/validation/psm/rules/messaging.evl` the value must be present and non-blank. `StandardQueueShouldNotUseFifoSuffix` (standard queue should not use fifo suffix) in `mde/validation/psm/rules/messaging.evl` the value must be present and non-blank. Transformation role: ETL rule `Queue2SqsQueue` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` assigns or materializes this feature while refining `SqsQueue`. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`. The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/naming.eol`.	A free-form `String`, subject to this class's semantic meaning and any EVL constraints. Example: `orders-events`.
`contentBasedDeduplication`	`Boolean` [1]	Records whether content based deduplication applies to sqs queue. This keeps the decision explicit even when the element's class or relationships remain unchanged. Transformation role: ETL rule `Queue2SqsQueue` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` assigns or materializes this feature while refining `SqsQueue`.	Either `true` or `false`. Example: `false`.
`deduplicationScope`	`String` [1]	Records the boundary within which deduplication scope is interpreted for the sqs queue. This keeps the decision explicit even when the element's class or relationships remain unchanged. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	A free-form `String`, subject to this class's semantic meaning and any EVL constraints. Example: `orders`.
`fifoThroughputLimit`	`String` [1]	Records the fifo throughput limit value for sqs queue. It keeps an operational boundary that should not be left to provider defaults explicit during review and transformation, so later steps do not have to infer it. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	A free-form `String`, subject to this class's semantic meaning and any EVL constraints. Example: `Sqs Queue Fifo Throughput Limit`.
`delaySeconds`	`Integer` [1]	Stores the delay seconds duration or limit, expressed in seconds on the sqs queue. The field records an operational boundary explicitly instead of leaving it to provider defaults. Semantic validation: `QueueTimingRangesValid` (queue timing ranges valid) in `mde/validation/psm/rules/messaging.evl` the value must remain absent in this modeling situation. Transformation role: ETL rule `Queue2SqsQueue` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` assigns or materializes this feature while refining `SqsQueue`. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	A numeric `Integer` value; use the unit or boundary documented for this attribute. Example: `1`.
`maximumMessageSize`	`Integer` [1]	Stores the human explanation of maximum message size on the sqs queue. The field records human review and generated guidance as an explicit, reviewable input. Semantic validation: `QueueMessageSizeRangeValid` (queue message size range valid) in `mde/validation/psm/rules/messaging.evl` the value must remain absent in this modeling situation. Transformation role: ETL rule `Queue2SqsQueue` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` assigns or materializes this feature while refining `SqsQueue`. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	A numeric `Integer` value; use the unit or boundary documented for this attribute. Example: `1`.
`messageRetentionPeriodSeconds`	`Integer` [1]	Records the human explanation of message retention period seconds for the sqs queue. This keeps the decision explicit even when the element's class or relationships remain unchanged. Semantic validation: `QueueTimingRangesValid` (queue timing ranges valid) in `mde/validation/psm/rules/messaging.evl` the value must remain absent in this modeling situation. Transformation role: ETL rule `Queue2SqsQueue` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` assigns or materializes this feature while refining `SqsQueue`. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	A numeric `Integer` value; use the unit or boundary documented for this attribute. Example: `1`.
`receiveMessageWaitTimeSeconds`	`Integer` [1]	Records the human explanation of receive message wait time seconds for the sqs queue. This keeps the decision explicit even when the element's class or relationships remain unchanged. Semantic validation: `QueueTimingRangesValid` (queue timing ranges valid) in `mde/validation/psm/rules/messaging.evl` the value must remain absent in this modeling situation. Transformation role: ETL rule `Queue2SqsQueue` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` assigns or materializes this feature while refining `SqsQueue`. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	A numeric `Integer` value; use the unit or boundary documented for this attribute. Example: `1`.
`visibilityTimeoutSeconds`	`Integer` [1]	Stores the visibility timeout seconds duration or limit, expressed in seconds on the sqs queue. The field records an operational boundary explicitly instead of leaving it to provider defaults. Semantic validation: `QueueTimingRangesValid` (queue timing ranges valid) in `mde/validation/psm/rules/messaging.evl` the value must remain absent in this modeling situation. Transformation role: ETL rule `Queue2SqsQueue` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` assigns or materializes this feature while refining `SqsQueue`. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	A numeric `Integer` value; use the unit or boundary documented for this attribute. Example: `30`.
`kmsDataKeyReusePeriodSeconds`	`Integer` [1]	For a sqs queue, the model records the kms data key reuse period seconds duration or limit, expressed in seconds. Keeping the fact with its owning element lets validation and refinement inspect it before artifact generation. Transformation role: ETL rule `Queue2SqsQueue` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` assigns or materializes this feature while refining `SqsQueue`. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	A numeric `Integer` value; use the unit or boundary documented for this attribute. Example: `1`.
`sqsManagedSseEnabled`	`Boolean` [1]	Records whether sqs managed sse enabled applies to sqs queue. The field records an explicit architectural or governance decision as an explicit, reviewable input. Semantic validation: `ProductionQueueShouldBeEncrypted` (production queue should be encrypted) in `mde/validation/psm/rules/messaging.evl` the related value or object must be explicitly provided. Transformation role: ETL rule `Queue2SqsQueue` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` assigns or materializes this feature while refining `SqsQueue`. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	Either `true` or `false`. Example: `true`.
`queueType`	`SqsQueueType` [1]	Records the controlled classification or strategy for queue type in the sqs queue. This keeps the decision explicit even when the element's class or relationships remain unchanged. Semantic validation: `FifoQueueNameSuffix` (fifo queue name suffix) in `mde/validation/psm/rules/messaging.evl` the feature participates in a semantic validation condition. `StandardQueueShouldNotUseFifoSuffix` (standard queue should not use fifo suffix) in `mde/validation/psm/rules/messaging.evl` the feature participates in a semantic validation condition. Transformation role: ETL rule `Queue2SqsQueue` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` assigns or materializes this feature while refining `SqsQueue`. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	Exactly one of: `STANDARD`, `FIFO`. Example: `STANDARD`.

Relationships

Relationship	Kind and multiplicity	Meaning in the model
`redrivePolicy` → `SqsRedrivePolicy`	containment, [?]	Contains the sqs redrive policy element(s) that make up this sqs queue; the contained objects belong to this model element.
`redriveAllowPolicy` → `SqsRedriveAllowPolicy`	containment, [?]	Contains the sqs redrive allow policy element(s) that make up this sqs queue; the contained objects belong to this model element.
`kmsKey` → `KmsKey`	reference, [?]	References the kms key element(s) used as kms key by this sqs queue; the target may be shared elsewhere in the model.
`queuePolicies` → `SqsQueuePolicy`	reference, [*]; opposite `queues`	References the sqs queue policy element(s) used as queue policies by this sqs queue; the target may be shared elsewhere in the model.

`SqsRedrivePolicy`

Represents sqs redrive policy in the PSM vocabulary. It specializes TraceableElement with the details needed for this modeling concern.

Direct supertypes: TraceableElement. Inherited attributes and marker capabilities are documented in the shared kernel; this section lists every attribute declared by this class.

Declared attributes

Attribute	Type and multiplicity	What it captures and why it exists	Accepted values and example
`maxReceiveCount`	`Integer` [1]	Stores the max receive count value on the sqs redrive policy. The field records an operational boundary explicitly instead of leaving it to provider defaults. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	A numeric `Integer` value; use the unit or boundary documented for this attribute. Example: `1`.

Relationships

Relationship	Kind and multiplicity	Meaning in the model
`deadLetterQueue` → `SqsQueue`	reference, [1]	References the sqs queue element(s) used as dead letter queue by this sqs redrive policy; the target may be shared elsewhere in the model.

`SqsRedriveAllowPolicy`

Represents sqs redrive allow policy in the PSM vocabulary. It specializes TraceableElement with the details needed for this modeling concern.

Direct supertypes: TraceableElement. Inherited attributes and marker capabilities are documented in the shared kernel; this section lists every attribute declared by this class.

Declared attributes

Attribute	Type and multiplicity	What it captures and why it exists	Accepted values and example
`redrivePermission`	`String` [1]	Records the redrive permission value for sqs redrive allow policy. It keeps this decision explicit during review and transformation, so later steps do not have to infer it. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	A free-form `String`, subject to this class's semantic meaning and any EVL constraints. Example: `Sqs Redrive Allow Policy Redrive Permission`.

Relationships

Relationship	Kind and multiplicity	Meaning in the model
`sourceQueues` → `SqsQueue`	reference, [*]	References the sqs queue element(s) used as source queues by this sqs redrive allow policy; the target may be shared elsewhere in the model.

`SqsQueuePolicy`

Represents sqs queue policy in the PSM vocabulary. It specializes AwsResource with the details needed for this modeling concern.

Direct supertypes: AwsResource. Inherited attributes and marker capabilities are documented in the shared kernel; this section lists every attribute declared by this class.

Declared attributes

Attribute	Type and multiplicity	What it captures and why it exists	Accepted values and example
`policyDocumentJson`	`String` [1]	Records serialized JSON representation of policy document for sqs queue policy. It keeps preserving structured provider or contract detail explicit during review and transformation, so later steps do not have to infer it. The repository contains no direct EVL rule, ETL assignment, or artifact-generator read for this declared field. For now, it remains a model-level fact for review and future refinement.	A free-form `String`, subject to this class's semantic meaning and any EVL constraints. Example: `{"enabled":true}`.

Relationships

Relationship	Kind and multiplicity	Meaning in the model
`policyDocument` → `IamPolicyDocument`	containment, [?]	Contains the iam policy document element(s) that make up this sqs queue policy; the contained objects belong to this model element.
`queues` → `SqsQueue`	reference, [+]; opposite `queuePolicies`	References the sqs queue element(s) used as queues by this sqs queue policy; the target may be shared elsewhere in the model.

`SnsTopic`

Represents sns topic in the PSM vocabulary. It specializes AwsResource, S3NotificationDestination with the details needed for this modeling concern.

Direct supertypes: AwsResource, S3NotificationDestination. Inherited attributes and marker capabilities are documented in the shared kernel; this section lists every attribute declared by this class.

Declared attributes

Attribute	Type and multiplicity	What it captures and why it exists	Accepted values and example
`topicName`	`String` [1]	Records the stable name/key/code used for topic name for the sns topic. This keeps the decision explicit even when the element's class or relationships remain unchanged. Semantic validation: `FifoTopicNameSuffix` (fifo topic name suffix) in `mde/validation/psm/rules/messaging.evl` the value must be present and non-blank. Transformation role: ETL rule `Topic2SnsTopic` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` assigns or materializes this feature while refining `SnsTopic`. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`. The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/naming.eol`.	A free-form `String`, subject to this class's semantic meaning and any EVL constraints. Example: `orders-events`.
`fifoTopic`	`Boolean` [1]	Records whether fifo topic applies to sns topic. The field records an explicit architectural or governance decision as an explicit, reviewable input. Semantic validation: `FifoTopicNameSuffix` (fifo topic name suffix) in `mde/validation/psm/rules/messaging.evl` the flag must be enabled for this rule to pass. Transformation role: ETL rule `Topic2SnsTopic` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` assigns or materializes this feature while refining `SnsTopic`. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	Either `true` or `false`. Example: `false`.
`contentBasedDeduplication`	`Boolean` [1]	Records whether content based deduplication applies to sns topic. The field records an explicit architectural or governance decision as an explicit, reviewable input. Transformation role: ETL rule `Topic2SnsTopic` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` assigns or materializes this feature while refining `SnsTopic`.	Either `true` or `false`. Example: `false`.
`displayName`	`String` [1]	The human-facing label used when the modeler needs a readable name distinct from the technical identity. Here it is attached to the sns topic, so the shared meaning travels with this particular model element. Transformation role: ETL rule `Topic2SnsTopic` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` assigns or materializes this feature while refining `SnsTopic`. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`. The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/naming.eol`.	A free-form `String`, subject to this class's semantic meaning and any EVL constraints. Example: `SnsTopicExample`.
`dataProtectionPolicyJson`	`String` [1]	Stores the serialized JSON representation of data protection policy on the sns topic. The field preserves structured provider or contract detail as an explicit, reviewable input. The repository contains no direct EVL rule, ETL assignment, or artifact-generator read for this declared field. For now, it remains a model-level fact for review and future refinement.	A free-form `String`, subject to this class's semantic meaning and any EVL constraints. Example: `{"enabled":true}`.
`deliveryStatusLoggingJson`	`String` [1]	For a sns topic, the model records the serialized JSON representation of delivery status logging. Keeping the fact with its owning element lets validation and refinement inspect it before artifact generation. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	A free-form `String`, subject to this class's semantic meaning and any EVL constraints. Example: `{"enabled":true}`.

Relationships

Relationship	Kind and multiplicity	Meaning in the model
`kmsKey` → `KmsKey`	reference, [?]	References the kms key element(s) used as kms key by this sns topic; the target may be shared elsewhere in the model.
`subscriptions` → `SnsSubscription`	reference, [*]; opposite `topic`	References the sns subscription element(s) used as subscriptions by this sns topic; the target may be shared elsewhere in the model.
`topicPolicies` → `SnsTopicPolicy`	reference, [*]; opposite `topics`	References the sns topic policy element(s) used as topic policies by this sns topic; the target may be shared elsewhere in the model.

`SnsSubscription`

Represents sns subscription in the PSM vocabulary. It specializes AwsResource with the details needed for this modeling concern.

Direct supertypes: AwsResource. Inherited attributes and marker capabilities are documented in the shared kernel; this section lists every attribute declared by this class.

Declared attributes

Attribute	Type and multiplicity	What it captures and why it exists	Accepted values and example
`endpoint`	`String` [1]	Stores the endpoint value on the sns subscription. The field keeps the model explicit and reviewable during review and transformation instead of leaving the decision to an inferred default. Semantic validation: `SubscriptionHasEndpointOrResource` (subscription has endpoint or resource) in `mde/validation/psm/rules/messaging.evl` the value must be present and non-blank. Transformation role: ETL rule `Subscription2SnsSubscription` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` assigns or materializes this feature while refining `SnsSubscription`. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	A free-form `String`, subject to this class's semantic meaning and any EVL constraints. Example: `Sns Subscription Endpoint`.
`rawMessageDelivery`	`Boolean` [1]	For a sns subscription, the model records the human explanation of raw message delivery. Keeping the fact with its owning element lets validation and refinement inspect it before artifact generation. Transformation role: ETL rule `Subscription2SnsSubscription` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` assigns or materializes this feature while refining `SnsSubscription`. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	Either `true` or `false`. Example: `false`.
`deliveryPolicyJson`	`String` [1]	Records the serialized JSON representation of delivery policy for the sns subscription. This keeps the decision explicit even when the element's class or relationships remain unchanged. Transformation role: ETL rule `Subscription2SnsSubscription` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` assigns or materializes this feature while refining `SnsSubscription`. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	A free-form `String`, subject to this class's semantic meaning and any EVL constraints. Example: `{"enabled":true}`.
`replayPolicyJson`	`String` [1]	For a sns subscription, the model records the serialized JSON representation of replay policy. Keeping the fact with its owning element lets validation and refinement inspect it before artifact generation. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	A free-form `String`, subject to this class's semantic meaning and any EVL constraints. Example: `{"enabled":true}`.
`filterPolicyScope`	`SnsFilterPolicyScope` [1]	Records boundary within which filter policy scope is interpreted for sns subscription. It keeps isolation and ownership decisions explicit during review and transformation, so later steps do not have to infer it. Transformation role: ETL rule `Subscription2SnsSubscription` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` assigns or materializes this feature while refining `SnsSubscription`. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	Exactly one of: `MESSAGE_ATTRIBUTES`, `MESSAGE_BODY`. Example: `MESSAGE_ATTRIBUTES`.
`protocol`	`SnsProtocol` [1]	Records the controlled classification or strategy for protocol in the sns subscription. This keeps the decision explicit even when the element's class or relationships remain unchanged. Semantic validation: `ExternalHttpSubscriptionsShouldHaveDlq` (external http subscriptions should have dlq) in `mde/validation/psm/rules/messaging.evl` the feature participates in a semantic validation condition. Transformation role: ETL rule `Subscription2SnsSubscription` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` assigns or materializes this feature while refining `SnsSubscription`. ETL rule `Subscription2SnsSubscription` in `mde/transformations/pim-to-awspsm/data-messaging-events.etl` reads or derives this feature while refining `SnsSubscription`. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`. The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/values.eol`.	Exactly one of: `LAMBDA`, `SQS`, `HTTP`, `HTTPS`, `EMAIL`, `SMS`, `FIREHOSE`, `APPLICATION`. Example: `LAMBDA`.

Relationships

Relationship	Kind and multiplicity	Meaning in the model
`filterRules` → `SnsFilterRule`	containment, [*]	Contains the sns filter rule element(s) that make up this sns subscription; the contained objects belong to this model element.
`topic` → `SnsTopic`	reference, [1]; opposite `subscriptions`	References the sns topic element(s) used as topic by this sns subscription; the target may be shared elsewhere in the model.
`endpointResource` → `AwsResource`	reference, [?]	References the aws resource element(s) used as endpoint resource by this sns subscription; the target may be shared elsewhere in the model.
`deadLetterQueue` → `SqsQueue`	reference, [?]	References the sqs queue element(s) used as dead letter queue by this sns subscription; the target may be shared elsewhere in the model.

`SnsFilterRule`

Represents sns filter rule in the PSM vocabulary. It specializes TraceableElement with the details needed for this modeling concern.

Direct supertypes: TraceableElement. Inherited attributes and marker capabilities are documented in the shared kernel; this section lists every attribute declared by this class.

Declared attributes

Attribute	Type and multiplicity	What it captures and why it exists	Accepted values and example
`fieldPath`	`String` [1]	Records the data location or endpoint represented by field path for the sns filter rule. This keeps the decision explicit even when the element's class or relationships remain unchanged. Semantic validation: `FilterRuleHasValues` (filter rule has values) in `mde/validation/psm/rules/messaging.evl` the value must be present and non-blank. Generation role: The artifact generator references this feature in `mde/generation/awspsm-to-artifacts/lib/cfn.eol`.	A free-form `String`, subject to this class's semantic meaning and any EVL constraints. Example: `/orders/{orderId}`.
`operator`	`String` [1]	Stores the operator value on the sns filter rule. The field keeps the model explicit and reviewable during review and transformation instead of leaving the decision to an inferred default. Semantic validation: `FilterRuleHasValues` (filter rule has values) in `mde/validation/psm/rules/messaging.evl` the value must be present and non-blank.	A free-form `String`, subject to this class's semantic meaning and any EVL constraints. Example: `>=`.
`values`	`String` [*]	Stores the values value on the sns filter rule. The field keeps the model explicit and reviewable during review and transformation instead of leaving the decision to an inferred default. Semantic validation: `FilterRuleHasValues` (filter rule has values) in `mde/validation/psm/rules/messaging.evl` the value must be present and non-blank.	A collection of values. Example: [`READY`, `READY-2`].

Relationships

This class declares no direct relationships.

`SnsTopicPolicy`

Represents sns topic policy in the PSM vocabulary. It specializes AwsResource with the details needed for this modeling concern.

Direct supertypes: AwsResource. Inherited attributes and marker capabilities are documented in the shared kernel; this section lists every attribute declared by this class.

Declared attributes

Attribute	Type and multiplicity	What it captures and why it exists	Accepted values and example
`policyDocumentJson`	`String` [1]	For a sns topic policy, the model records the serialized JSON representation of policy document. Keeping the fact with its owning element lets validation and refinement inspect it before artifact generation. The repository contains no direct EVL rule, ETL assignment, or artifact-generator read for this declared field. For now, it remains a model-level fact for review and future refinement.	A free-form `String`, subject to this class's semantic meaning and any EVL constraints. Example: `{"enabled":true}`.

Relationships

Relationship	Kind and multiplicity	Meaning in the model
`policyDocument` → `IamPolicyDocument`	containment, [?]	Contains the iam policy document element(s) that make up this sns topic policy; the contained objects belong to this model element.
`topics` → `SnsTopic`	reference, [+]; opposite `topicPolicies`	References the sns topic element(s) used as topics by this sns topic policy; the target may be shared elsewhere in the model.