Create: Prospects can be created with a referenced email address.
If AMPSEA is enabled and you call the create API with the same email address multiple times, each call creates a prospect.
Read/Query: When making a read query, querying by email returns all prospects that share that email address.
Querying by Account Engagement id only returns the one matching prospect.
Update: In version 5, an update must specify a prospect by id. In version 3 it was possible to specify a prospect by email address.
upsertLatestByEmail: UpsertLatestByEmail will find the most recently updated prospect by the email supplied and upsert that record. If a record with that email does not exist, one will be created.
See Upserting Prospects for more details.
Delete: Delete query must be referenced by Account Engagement id.
The V5 API has updated the forms API has been expanded to include several new features including creating forms, reordering form fields, adding/removing tags, and copying to CMS.