Brands of Salt
For those of you who wonder why some recipes call for almost double the amount of salt, here's an article about brands of salt that provides some insight. I've dealt with this many times, and a good example is the Compost Cookie recipe from Momofuku via Regis and Kelly, which calls for 2 teaspoons of Kosher salt. They're using Diamond brand kosher which is coarser than what a lot of people use (Morton Kosher). So if you use 2 teaspoons of Morton, your cookies will be too salty. If you use 2 teaspoons of table, they'll be barely edible.