h: The ID of the node ;
p: The ID of the parent node (directory) ;
u: The owner of the node ;
t: The type of the node:
0: File
1: Directory
2: Special node: Root (“Cloud Drive”)
3: Special node: Inbox
4: Special node: Trash Bin
a: The attributes of the node. Currently only contains its name.
k: The key of the node (used to encrypt its content and its attributes) ;
s: The size of the node ;
ts: The time of the last modification of the node.
Source: http://julien-marchand.fr/blog/using-the-mega-api-with-php-examples/