Ok, I asked this same question on the Aussie forum as well and this is the reply I got.
John
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Their rug making was far more detailed than we realise, incorporating very significant symbols into their design other than the 'bits of colour' associated with Berber in western society.
In relation to Berbers as we know them now, that is as carpet, it is loop or cut pile carpet with earthy coloured slubbings in the yarn, or loosely termed, blobs of colour throughout the yarn.
Or to quote Australian Standards 2454:2007 Terminology,
Berber
"The effect given by a mixture of earthy tones similar to those of naturally pigmented wools, in a flecked or mottled pattern. (See also Flecks) (Compare with Tweed)
Flecks
"The effect given by incorporating small fragments of differently coloured or toned yarn into the pile yarn, such as with Berber yarns or tweed yarns."
Tweed
"The effect given by incorporating flecks of various colours into a pile yarn similar to a Berber effect, except with colours other than earthy tones."