"..........showing in greater or less degree a decided kink or bend near the tip" (The 1911 Encyclopedia Britannica).
The Siamese cat is also known to have had (and probably still does in Asia), a shortened tail due to a recessive gene (br) mutation. The Mekong Bobtail is a bobtailed Siamese cat!
In other Siamese you might see a kinked tail or swollen tail (due to fused vertebrae). The shortened tail and the kinked Siamese tail may be different expressions of the same gene.
Selective cat breeding has religiously bred out what is considered a deformity in the kinked tail. It is now outlawed by the cat fancy whereas once it was considered interesting.
Apparently the kinked tail in Siamese cats still pops up in breeder litters. It would seem that getting rid of the Siamese kinked tail from breeding lines is proving difficult.
|Not a Siamese cat but Siamese cats are black with the Siamese gene which creates|
the pointing. This picture shows the kinked tail very clearly.
See much more on this subject from a book published in 1889 and written by the founder of the cat fancy, Harrison Weir.