Which part of Kernel contains /Documnetation/DocBook?

[hutx]

I am buliding a project which needs to complile linux
Kernel.
It builds
/usr/src/kernels/2.6.18-1.2798.fc6-i686/Documentation/DocBook/Makefile.
I do have the dir
/usr/src/kernels/2.6.18-1.2798.fc6-i686/. But I do not
have the dir Documentation/DocBook. I want to use
"make menuconfig" to install it. I do not know which
one item I need to select.

Please help me. Thanks a lot.