Query Activity

https://help.salesforce.com/s/articleView?id=sf.mc_as_using_the_query_activity.htm&type=5

Wait Activity

https://help.salesforce.com/s/articleView?id=sf.mc_as_wait_activity.htm&type=5

OAuth API Integration

https://developer.salesforce.com/docs/marketing/marketing-cloud/guide/integration-considerations.html

SMS/MMS Content

https://help.salesforce.com/s/articleView?id=sf.mc_moc_message_content_considerations.htm&type=5