Anyone who spots examples of journalists using such terms can send a free postcard to send to the offending publication or broadcaster.
Stephen Corry, director of Survival International, says: "When newspapers talk about tribal people, they often use descriptions such as 'primitive' and 'Stone Age', which suggest they are backward."
Corry believes ignorance rather than conscious prejudice is behind this.
"When people have a better understanding of the issue, they usually refrain from using such language," he adds.
The way language can influence the way minority groups are perceived has been debated fiercely since the subject was raised by editor Dominic Lawson in a column for The Independent last month.
Lawson referred to his own daughter, who has Down's Syndrome, as "mentally handicapped", sparking a flurry of letters to the newspaper and a Radio 4 debate. Lawson wrote: "The description is neither inaccurate, nor does it imply any moral fault or lack of common humanity. Nor, so far as I am aware, has the term ever been used as an insult."
One problem, of course, is that, as language develops, once acceptable terms become unacceptable.
Marie Benton, communications officer at the Down's Syndrome Association, says: "People with Down's Syndrome used to be described as 'mongols' and those with learning disabilities as 'idiots', and 'imbeciles'. These were medical classifications, but they came to be perjorative. Any label associated with disability acquires stigma over time."
Jo William, chief executive of Mencap, agrees. "The challenge for us is to find ways to describe people with impairments that don't stigmatise," she says.
A charity that knows well how time can change meaning is Scope, which changed its name from the Spastics Society in 1994. Ruth Scott, external affairs manager at the charity, says: "We were lobbied by disabled people to change because the word had become offensive. Perhaps one day 'handicapped' will be reclaimed as a term of pride - but only disabled people themselves can do it."