chapters in R reference manual and documentation u

Question

Once I've seen a package supporting R program in which his documentation and reference manual was divided into chapters ( they were called by the consecutive letters of the alphabet ) so that an user could see that functions presented by that package are divided into groups.

Now I'm trying to do the same. I'm building package using roxygen2 package but can not deal with that problem.

Can any1 has any solution ? So in that case my documentation will be split to a file like this:

Group1:

funAX
funBX
funCX

Group2:

funAY
funBY
funCY

instead of

funAX
funAY    
funBX
funBY
funCX    
funCY

A name of package that provides that solution will also be helpful.

Answer 1

In the lattice package developers invented a way to order a documentation. They simply add letters in an alfabetic order to the beginning of a .Rd file. This order might suggest the way of passing thru the manual to optimize understanding. Manual is here.