# Rules For Naming Diagram Entities

Occasionally you will try to name a Stock, Flow or Converter on the diagram and the name will keep popping back to its previous name. Since the names you choose for Stocks, Flows and Converters will be used by the software as part of equations, the software will enforce rules about which characters can be used for naming them.

- No Stock, Flow or Converter name can begin with a number of any of the following: ! # % &. You can use a number or one of these characters in the middle of the name or place them at the end, but do not use them at the beginning of the name.

- You cannot use the same name twice in the same model.

- You cannot use the following characters anywhere in a Stock, Flow or Converter name:

. , < > - — / += = * ( ) ^ [ ] { }

However, you can use: \ @ $