Constant BOUND_RESOURCE_PREFIX 

pub const BOUND_RESOURCE_PREFIX: &'static str;

What a resource id starts with when a window publishes it under the toolkit’s transport alias: <prefix><host>:<publication>:<hex of the app's own id>. The window’s actions are addressed by the alias; the app names the resource by its own id (a selection’s subject does), so a reader matching the two decodes the alias (logical_resource_id).