Marc Shapiro writes in the Aug. 18, 2008 issue of the Forward:
The very meaning of glatt kosher in the United States is not what most people think, namely, meat that has no adhesions. While this is indeed the original meaning of glatt and the meaning most people identify it with, the word as used today means something more expansive, depending on which kashrut organization you ask.
For some, it simply means that they hold themselves to a very high halachic standard in all areas of meat production. For others, it means that they permit only a couple of small, easily removed adhesions, a type of glatt that was actually quite common among Hasidim in prewar Europe. One thing that is certain is that glatt in the United States does not mean that an animal’s lung is completely smooth. Sephardim, who are supposed to eat only real glatt, are under normal circumstances not permitted to eat the typical “American glatt,” and they therefore have their own special “Beit Yosef glatt.”
While the kashrut organizations have not exactly hidden this information, and will tell you the truth if you ask, they have not been exactly forthcoming about it either. There is, for example, no explanation on the O.U. Web site as to what it means when it stamps a product glatt. The closest you get is an article titled the “The Kosher Primer,” which explains that real glatt is free of all adhesions on its lungs. The primer does acknowledge that, “Recently, the term ‘glatt kosher’ is increasingly used more broadly as a generic phrase, implying that the product is kosher without question.” Yet there is no clarification that the O.U.’s glatt falls into the second category — which also explains how the organization believes it appropriate to certify “glatt chickens.”
