SYSCTL_XXX(9) manual page deficiency

Hi,

According to the manual page for the SYSCTL_XXX(9) family of functions, 
in order to use them one needs to include sys/types.h and sys/sysctl.h. 
However, if you do just that the code doesn't compile due to missing 
DATA_SET() macros, which is defined in sys/linker_set.h. My question is 
whether or not sysctl.h should include sys/linker_set.h or manual page 
to be extended to also suggests that this include is required to use 
those functions?

-Maxim