The ZZ will be a single of double character country code.

FORBES: How Do I Correctly Identify My iPhone So I Can Sell It?

The HIV retrovirus, in particular, is a single-stranded RNA virus that duplicates itself in a host cell by converting its genetic code into double-stranded DNA that is then inserted into the host cell.

FORBES: Progress in Drug Therapy Marks the 25th Anniversary of World AIDS Day

The way we're going to create jobs here is not just to change our tax code, but also to double our exports.

WHITEHOUSE: The White House

The famous "molecule of life", which carries our genetic code, is more familiar to us as a double helix.

BBC: 'Quadruple helix' DNA seen in human cells

The flagship Quadro 5010M features Error Correction Code (ECC) and fast, 64-bit double precision capabilities to ensure the greatest accuracy and fidelity of results.

ENGADGET: NVIDIA debuts new slew of Quadro mobile GPUs, each sporting Optimus for battery life too

They want to double down on some of the inequities that already exist in the tax code.

WHITEHOUSE: President Obama Speaks on the Buffett Rule

Sometimes the tax code goes overboard in the other direction, however, subjecting some income to double taxation.

FORBES: The 'Tax Expenditure' Con Job