What's the difference between mehadrin and non-mehadrin certifications. (e.g. at http://www.kosherinjerusalem.com/where_to_eat/kosher-hotels)
How can I find out which hechsheirim are reliable and which ones aren't?
I have noticed that many cans of pepsi don't have a hechsher (kosher symbol) on them. Do they need one?
The OU used to put DE next to the OU symbol when a product was Dairy Equipment. Such a product can not be eaten with meat but can be eaten right afterwards (you don't need to wait the amount of time ...