Like https://docs.telerik.com/blazor-ui/components/combobox/custom-value and https://www.telerik.com/kendo-angular-ui/components/dropdowns/multiselect/custom-values/ so the user can input tags on their own without them being in the app data source.

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ADMIN EDIT

The following sample may be useful in implementing this in the meantime: https://github.com/telerik/blazor-ui/tree/master/multiselect/add-new-item

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