In the answer given by Rabbi Blass, it seems that an inaccurate assumption that "Kosher gelatine" is from a kosher animal that was slaughtered according to kosher regulations. In the USA major brand names for yogurt that carry a respectable kosher certification (i.e. OU) do not have such certification for their products that list "kosher gelatin" on the label. This is quit suspicous. Presently, there are various kosher organizations that certify gelatin even if the source is from pig stretching the heter that the process renders the gelatin non fit for a dog, thus the resulting gelatin is kosher. This opinion is not accepted as the process is done intenionally and then is corrected. In addition, products with such labels "Kosher gelatin" and carry a "K" do not have rabbinacal supervision. The letter "K" can be put on any product by any producer as this is not a copy wtited symbol. The conclusion is that product labels listing "kosher gelatin" that is not certified kosher by a reliable kashrut organization (not just the letter "K") are not acceptable.
There are differences among the poskim as to the kashrut of gelatine from non-kosher animal sources- bones, dried skins,meat. You are correct in asserting that only products certified kosher by a respected kashrut organization are kosher.