Create your first rule

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Create your first rule

This example reports doors whose Mark parameter is empty.

1. Open the configuration folder

On the Diagnostics pane, press Open configuration folder. Each Revit version has its own folder.

Create diagnostics.config.yaml, or open the existing file. If you loaded the welcome examples, use them as a starting point instead of replacing the file.

2. Add the rule

Add this entry to the rules: list of diagnostics.config.yaml:

- type: "custom"
  code: "CSTM201"
  description: "Doors without a mark"
  message: "'{elementName}' ({elementId}) has an empty mark."
  severity: "Warning"
  takeDocument: "!property('IsFamilyDocument')"
  take: "instance and builtincategory('OST_Doors')"
  check: "!isnullorempty(parameter(me, 'ALL_MODEL_MARK'))"

take selects door instances. check returns true for a door with a mark, so a door with an empty mark appears in the report. The built-in parameter name keeps the rule independent of the Revit interface language.

3. Check the result

Save the file, return to Revit, enable CSTM201 in Diagnostics, and press Run in Diagnostic results. Test the rule on a disposable model or copy first.

If the rule does not appear, check the exact file name and folder, then see Troubleshooting. For more fields and formula options, continue with User diagnostics and Formula syntax.

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