STERN message greets visitors to a small town in one of outback Australia's most isolated regions: "Warning."

到澳大利亚内陆最偏远地区一个小镇的拜访者常常被严肃警告：“警告。”

youdao

The mere fact that the IRS issues a summons rather than an IDR sends a stern message.

FORBES: What To Do If You Get An IRS Summons

He sent a very stern message to the Turkish government, that the offensive should wrap up within days.

NPR: McCain, Obama Tussle over Iraq

Meaning, that they feel like they've sent a stern message to Washington.

NPR: Iran Detains Iranian-American Scholar