This may be a characteristic seen on other envelopes he has sent.

CNN: FBI profiles anthrax letter writer

Knowing your strengths and weaknesses may be the most important characteristic to seeking excellence.

FORBES: Do You Prefer Success Or Achievement?

Liquidity may not be the first characteristic you think about when evaluating a potential investment, but it is something to factor in to your decision.

FORBES: Know When To Sell

Some say Mr. Abe's characteristic impatience may be beginning to surface as he tries to address nationalistic causes dear to his heart while his economic policy is still earning praise and his approval ratings remain high.

WSJ: Japanese Politicians' Visit to Shrine Sparks Backlash

"You may be losing stem cells in the process or changing the characteristic that shows these cells where to home, " says Hal E.

FORBES: Cell makers

In characteristic Apple fashion, they look like they may be able to emerge as the only dominant force in the market in no time at all.

FORBES: Apple Sold 350K Digital Textbooks in Three Days, But What Comes Next?

Also, the analysis of samples is a powerful tool to identify any agent that may be present, even if in small concentrations, or of characteristic degradation products that would demonstrate its past presence.

BBC: How to investigate chemical weapons allegations

It may be unfortunate that Vint Cerf and the other network pioneers chose to name their network after its most distinguishing technical characteristic rather than give it a proper name, but that does not allow us to disregard the distinction.

BBC: Computer user