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Supported tags are: scope,  addToElementsScope, logWhenOverMax, allowaccess, directEdit, useAsCaptionInDeveloper + captionPriority, showInOutlineView, main and main mode. 

scope: Restricts the model property to: 'design', 'runtime' or 'private'. 

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If a property should allow the developer to choose in the properties view from a predefined set of values you can use the "values" attribute in combination with "default" and optionally "mode" tag (see above) (default can be one of the predefined values but can also be something else):

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