LSB1.1: /proc/cpuinfo

[Alan Cox]

> Then, in general the specification should state that any options not
> documented, but found to be present in any command/function, should
> not be used as they will not have been tested and results cannot be
> guaranteed.

The LSB doesn't define what happens when you use a command or library
function that is not in the LSB. If you use glibc internal functions you
will get burned (especially if the folks trying to replace glibc with 
something much lighter actually succeed)