Shot Across The Bow Meaning

(idiomatic) A warning that negative consequences will be faced if something is carried out or allowed to continue.

Example: 2007, David Geltner, Norman G. Miller, Jim Clayton, & Piet Eicholtz, Commercial Real Estate Analysis and Investments, Cenage Learning, Inc. (2010), ISBN 9780324382143, page 397:
  This is often used as a "shot across the bow," warning the borrower how seriously the lender views the default.
2007, Jeffrey Toobin, The Nine: Inside the Secret World of the Supreme Court, Anchor Books (2008), ISBN 9781400096794, page 180:
  This was a shot across the bow of the Florida justices, a warning against further activism in this case, but one with relatively little practical significance at this late date.
2008, Chris Lauer, The Management Gurus: Lessons from the Best Management Books of All Time, Portfolio (2008), ISBN 9781591842088, unnumbered page:
  Before punishing, place a shot across the bow — provide a clear warning to let people know exactly what negative things will happen should they continue down their current path, but don't actually administer discipline yet.