vm_map_find

[Alexej Sokolov]

Hello,
my question is about vm_map_find (9)
 int
 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
         vm_offset_t *addr, vm_size_t length, boolean_t find_space,
         vm_prot_t prot, vm_prot_t max, int cow);

Could anyone explain what exactly parameter "cow" for ? Which values and
meanings ?
man page dives not enough informations about it.

Thanks