ICF

Jette AM. (2006). Toward a Common Language for Function, Disability, and Health. Physical Therapy, 86(5), 726-734.

"The World Health Organization (WHO) has developed internationally accepted classifications with the intent of providing a framework to classify and code information about health and to equip the international community with a standardized language that would facilitate communication about health across the globe and across various disciplines."
Jette AM. (2005). The Changing Language of Disablement. Physical Therapy, 85(2), 118-119.

"In June 2008, APTA joined the World Health Organization (WHO), the World Confederation for Physical Therapy, ... in endorsing the International Classification of Functioning, Disability and Heath (ICF). With this endorsement, ICF language will be incorporated into all relevant association publications, documents, and communications through existing planned review and revision cycles."
APTA (2009). ICF: The International Classification of Functioning, Disability, and Health Resources. Retrieved 8-14-2009. http://www.apta.org/AM/Template.cfm?Section=Info_for_Clinicians&TEMPLATE=/CM/ContentDisplay.cfm&CONTENTID=51425

2. Evolution of the ICF
(abbreviated) PowerPoint from the WHO (just 5 slides).
World Health Organization. (2009). International Classification of Functioning, Disability and Health (ICF). Retrieved 10-18-2009. http://www.who.int/classifications/icf/en/

5. What is an ICF "Core Set"?