Whenever an Entity Id (may be called Survey Id, List Id etc depending on the specific API) can be specified, you can pass in any of the unique Entity identifiers:

Entity Id (or Survey Id, List Id etc). NEON’s internal identifier.
Name. The unique Entity name. It’s case sensitive and consists of both upper and lowercase letters. The name is optionally prefixed with the ‘@’ sign.
External Id. An optional external identifier. Aways needs to be prefixed with the ‘$’ sign (to differentiate it from the other types).

Only PUBLISHED entities can be referenced by default, but this can be overridden by adding the query parameter includeUnpublished=true. This enables you to reference all INSTALLED Entities. Draft, Archived and Deleted Entities can never be referenced through the Loyalty API.

Sometimes the documentation states that you can pass in a list of Entity Ids. In this case you can enter more than one Entity Lookup Id, separated by comma.