This handler is called every time state of the feature is changed. It should be used to provide additional security for macro feature.

protected override swMacroFeatureSecurityOptions_e OnUpdateState(ISldWorks app, IModelDoc2 model, IFeature feature)
{
    //disallow editing or suppressing of the feature
    return swMacroFeatureSecurityOptions_e.swMacroFeatureSecurityCannotBeDeleted 
                | swMacroFeatureSecurityOptions_e.swMacroFeatureSecurityCannotBeSuppressed;
}