ASCII (United States)

modulename: nls_ascii.ko

configname: CONFIG_NLS_ASCII

Linux Kernel Configuration
└─>File systems
└─>Native language support
└─>ASCII (United States)
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
An ASCII NLS module is needed if you want to override the
DEFAULT NLS with this very basic charset and don't want any
non-ASCII characters to be translated.

source code:
depends
CONFIG_NLS