The key words in Janet L. Yellen’s news conference Wednesday were rather pithy, at least by central bank standards. “Just because we removed the word ‘patient’ from the statement doesn’t mean we are going to be impatient,” Ms. Yellen, the Federal Reserve chairwoman, said.

With this framing, Ms. Yellen was putting her firm stamp on the policy of an institution she has led for just over a year — and making clear that she will not be boxed in. Her words and accompanying announcements conveyed the message that the Yellen Fed has no intention of taking the support struts of low interest rates away until she is absolutely confident that economic growth will hold up without them.

Earlier Wednesday afternoon, the Fed’s policy committee had removed a promise to be “patient” about raising interest rates from its written statement, something financial markets have anticipated for months as a sign that interest rate increases are coming soon. But Ms. Yellen managed a delicate task of changing that language to obtain flexibility without setting the Fed on a preordained course to tighter money.

Ms. Yellen’s comments about patience versus impatience were part of that dance. But the dual message was even more powerful when combined with other elements of the central bank’s newly released information, which sent the signal that members of the committee intend to move cautiously on rate increases.