Hi there!
In a previous study exploring the scientific literature, we identified the state-of-the-art on the Scrum practice "Definition of Done" in agile projects. We discovered that companies use different levels of done. For instance, some companies use only 1 (e.g., release); others use 3 (e.g., story, sprint and release). The most popular types of criteria are related to software verification and validation and regulatory compliances.