(By Don Miller) In its continuing efforts to nurture the fragile economic recovery, the U.S. Federal Reserve is widely expected to leave interest rates at record lows when it concludes its meeting today (Wednesday).

However, observers will be closely examining the details of the language in the statement of the Federal Open Market Committee (FOMC) meeting for hints as to when it plans to change monetary policy.

The overwhelming consensus is that the Fed will hold the federal funds rate steady at near-zero until the second half of next year. But that assumes the economic growth will stay in line with the Fed's current forecast – a weak recovery with subdued inflation and slow growth.

The real internal debate between Fed Chairman Ben Bernanke and his colleagues is likely to focus on how to signal a change in stance to investors, businesses and everyday Americans when it anticipates raising rates.

Change to Two Phrases Will Signal Policy Reversal

The key language most analysts will focus on is the Fed's promise to keep rates "exceptionally low" for "an extended period." Bernanke has been using those two phrases since March, and an Oct. 23 report in the Financial Times set off a firestorm when it suggested that the Fed was considering scrapping them.  Any changes to those words in the FOMC statement could blow up the bond markets, according to some analysts.

"Suggestions that the Fed might fiddle with the ‘extended period' text of its statement are worrying," analysts at ING Groep NV (NYSE ADR: ING) told the FT. "This phrase is dynamite – and should be handled only with extreme caution, better not at all in our opinion."

Other analysts say the central bankers know the dangers involved and will avoid any changes for now.

"We don't expect them to move away from the extended-period language," Dean Maki, chief U.S. economist at Barclays Capital Inc.