In his rebuttal in today's oral argument, Deputy Solicitor General Malcolm Stewart made an interesting reference to trademarks that may constitute illegal insults to religion under the law of a foreign country:
The preparation of the principal register is not just an ancillary consequence of this program. It's the whole point to provide a list of trademarks so other people know what has been approved, what's off limits.
And the consequence of Mr. Connell's position is that the government would have to place on a principal register, communicate to foreign countries the biased racial epithets, insulting caricatures of venerated religious figures. The test for whether the government has to do that can't be coextensive with the test for whether private people can engage in that form of expression.....
... [T]he government, at the very least, has a significant interest in not incorporating into its own communications words and symbols that the public and foreign countries will find offensive.(See prior related posting.)