By adding the network tags from the relations onto features we know, for instance, that a way for "US 101" is network "US:US" and should have use US Route style artwork. But we can't shove the ref value into the shield's text straight because it duplicates "US ".

Two options:

• We modify the ref to strip out values like "US ", but this a destructive change and might impact other users of the data, especially non-Tangram users.
• We create a new shield text property and store the result there.