diff --git a/share/man/man9/kqueue.9 b/share/man/man9/kqueue.9
--- a/share/man/man9/kqueue.9
+++ b/share/man/man9/kqueue.9
@@ -22,7 +22,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd December 18, 2023
+.Dd November 24, 2025
 .Dt KQUEUE 9
 .Os
 .Sh NAME
@@ -197,6 +197,18 @@
 that the
 .Va knote
 was added to.
+.It Va f_copy
+The
+.Va f_copy
+function is called to copy notes when the process forks.
+When
+.Dv NULL ,
+no new note will be allocated in the child process.
+Filter might set
+.Dv f_copy
+to
+.Fn knote_triv_copy
+if there is no additional resource handling required, besides shallow copying of the knote itself.
 .El
 .Pp
 The function