How do you tell a wizard?

[seth.zirin]

A true wizard knows that sleep() takes two arguments and would never
invoke it except at base level.

A true wizard knows when and why PCATCH is needed and is capable of using
it.

A true wizard knows which subroutines return twice and which never return.

Many wizards still dislike the Berzerk strains of the kernel that once
permitted such vulgarities as Control-Zeeing a mkdir.  A genuine wizard
knows why...

Seth Zirin