If you forget something and need to go back and make another change please get in contact as soon as possible before the application is assessed. The SLIP team can reject an application once it is submitted and return it to a draft state so you can make the necessary changes and resubmit for approval. Recent new functionality makes it possible to cancel an application after the application has moved into the next phase however it will be deleted completely and you will need to raise another chagne and start again. 

Reference: For more information see the Application review article in the Publishing a new dataset series