TCO-99 are guidelines set forth by the Swedish governments (National Board for Measurement and Testing, MPR) and the Swedish Confederation of Professional Employees (TCO) to regulate emission properties of electrical equipment.
The guidelines cover such things as emissions, ergonomics, resolution, refresh rate, power consumption, and safety to name a few. Every few years TCO updates the requirements for display devices. TCO-99 is the latest standard older standards included TCO-95 and TCO-92, the oldest standard is MPR-II.
If you want a monitor that complies with the current standards get one with TCO-99 for more information see this
LINK
Jim Witkowski
MonitorsDirect.com