NFS client support for NFSv4.1 (DEVELOPER ONLY)

configname: CONFIG_NFS_V4_1

Linux Kernel Configuration
└─>File systems
└─>Network File Systems
└─>NFS client support for NFSv4.1 (DEVELOPER ONLY)
In linux kernel since version 2.6.31 (release Date: 2009-09-09)  
This option enables support for minor version 1 of the NFSv4 protocol
(draft-ietf-nfsv4-minorversion1) in the kernel's NFS client.

Unless you're an NFS developer, say N.