The GetImplicitResourceString method is invoked in the get accessor of the Title property, the Description property, and any custom attributes that are defined in the Attributes property. The SiteMapProvider provider by which the SiteMapNode object is tracked must have its EnableLocalization property set to true for the GetImplicitResourceString method to be called. If the EnableLocalization is set to false, localization is not performed and the GetImplicitResourceString method is never called.
If the GetImplicitResourceString method returns a string that is not empty, this becomes the value of the Title, Description, or custom attribute property.
The GetImplicitResourceString method uses the value of the ResourceKey property to localize the attribute. If the ResourceKey is not specified, the GetImplicitResourceString returns null.
The XmlSiteMapProvider class imposes the restriction that the SiteMapNode object cannot define both implicit resource expressions and explicit resource expressions for attributes. However, a custom provider implementation can choose to allow both.