The Wool Products Labeling Act of 1939 requires that a label state whether the wool used in a textile item is new or virgin (never before used in cloth) or recycled (includes fibers recovered from previously manufactured new or used cloth).
Recycled wool tends to be weaker than new wool because of its shorter fiber length. It is frequently blended with stronger synthetic fibers such as nylon or acrylic to make a more durable fabric. Recycled wool tends to shed more lint than new wool. Fabrics made from recycled wool may appear somewhat darker and duller in color. Recycled wool is sometimes used in lower-priced, heavy weight clothing, such as winter coats.
New or virgin wool is defined by the Wool Products Labeling Act of 1939 as wool that has never been used or reclaimed from any spun, woven, knitted, felted, manufactured or used product.
All-wool is fabric of any description in which yarns are 100 percent wool from sheep. Other wools, such as angora, alpaca, camel, cashmere, mink and rabbit are named for the animal providing the fiber. They must be present in amounts of 25 percent or more to alter the properties of the blend.
Woolen refers to a fabric that is thick and fuzzy. The wool fibers in the yarns are short and only partially straightened.
Worsted is a wool fabric that is smooth, lustrous and strong. The wool fibers in the yarn are long and have been straightened by combing.
Lambswool means that the fiber came from a younger animal up to seven months old. It is more likely to be soft and pleasant to touch.
Merino is a very fine, soft wool from the Merino sheep.
Wool felt is a non-woven fabric made by layering thin sheets of carded wool fibers and treating them with heat, moisture and pressure to produce a tight felted or matted fabric that does not fray or ravel. Felt is also made from acrylic and other fibers.
Bonded or laminated wool is wool-face fabric that is attached to a backing cloth to provide additional stability and body. The backing may be cotton, acetate knit, laminated foam or another fiber.'
This is USA anyway but I'm pretty certain it's fairly universal.