Is there any other property available in "pleeease" object in grunt.initConfig?

[newjie]

I just started to learn Grunt, I don't understand why there has to be a "custom" layer between "pleeease" object and its "options" in "grunt.initConfig". With the name being "custom", does it suggest there are other properties available in this layer? If yes, where can I find out how to build this "pleeease" object in detail? ( I know where to find out how to build "options" object, I am asking about the direct children of "pleeease" object.