Hello @Sigbjørn Herstad​, thanks for posting! I think its possible to write nested feature types using ID's with FME's XSD-Driven XML Writer. I think you'd also need to manually assign the parent/child ID's in the workspace. To write to alert and info as seperate feature types, we need to remove any info{} lists from the alert feature type (as we will be writing them seperately). We can use an AttributeRemover to remove the list: info{}.

Next, use a seperate data stream to Explode the list: info{}. Once the list(s) are exploded into features, an AttributeCreator can be used to assign xml_parent_id and xml_id. I've added a screenshot to help illustrate the process:

To add the info feature type: Writers > Import Feature Types > Feature Paths: 'cap:alert cap:alert/cap:info'. If you don't map the feature path or do not map it correctly, you likely won't get the correct output (important step!). I've attached the workspace to this post, you can find it attached as 2b-XSD-DrivenWriter-info.fmw. Please let me know if you have any questions about the workspace/process. I hope this answers your original question! Let me know. Happy to help, Kailin Opaleychuk