[QE-users] Why some of the keys used by input file start with &, some not?

[Hongyi Zhao]

Hi,

Just as the keywords list for the input file give here:

https://www.quantum-espresso.org/Doc/INPUT_PW.html

Some of them start with &, some not.  Why designed them in this quirky way?
I really cannot figure it out, any hints?

Regards
-- 
Hongyi Zhao <hongyi.zhao at gmail.com>