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The data source name is optional, if the field name is unique you can just reference that, e.g., `Tank Capacity gals`. You can also abbreviate data source and /or field names, e.g., `Tank Capacity` or `Entity.Site Name`. If you abbreviate and there are more than one matching column, it will pick the left most column in the calculation.
If you make an error in your syntax, the application will inform you where the error is occurring:
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