Of all the predefined constants, these three are different. They are the only ones to be case-insensitive.

Constants are case sensitive. Traditionally, we make them all-caps when defining them but that’s not necessary. The predefined constants, however, were defined uppercase and therefore must be used that way - except for these three, as I mentioned.

So how do you like to use them? Vote in the poll below and leave us your comments as to why you think that way.