Correct uml didn't have anything to say about relational databases. I use two types of diagrams: Erds and Random blocks and arrows and icons that mean whate

Correct uml didn't have anything to say about relational databases. I use two types of diagrams: Erds and Random blocks and arrows and icons that mean whatever I want them to mean for that particular diagram, based on whatever concept I want to communicate at that point. Maybe it's network architecture, maybe it's dataflows, maybe it's software components. Each diagram comes with some text explaining what it represents.