Index: ./share/man/man5/bsd.port.mk.5
===================================================================
RCS file: /home/cvs/src/share/man/man5/bsd.port.mk.5,v
retrieving revision 1.550
diff -u -p -u -p -r1.550 bsd.port.mk.5
--- ./share/man/man5/bsd.port.mk.5	22 Nov 2021 11:17:39 -0000	1.550
+++ ./share/man/man5/bsd.port.mk.5	12 Dec 2021 12:02:38 -0000
@@ -3562,6 +3562,7 @@ This is often because of confusion betwe
 RUN_DEPENDS is needed for dlopen'd libraries.
 .Pp
 Might be intentional sometimes, if some compile flavors create static binaries,
+or the port rebuild needs to be linked to the update of a runtime dependency
 for instance.
 Also, will happen for multi-packages, where one sets LIB_DEPENDS to have
 a given build dependency (and corresponding WANTLIB for a given SUBPACKAGE).
@@ -3569,6 +3570,18 @@ a given build dependency (and correspond
 See
 .Cm print-package-args Pq Cm lib-depends-args
 for details.
+.Pp
+Many ports are using
+.Xr dlopen 3
+to probe for a library and fall back to reduced functionality if it is
+not found.
+This makes it necessary to rebuild the port when the library is updated.
+In such a case, add it to WANTLIB and LIB_DEPENDS.
+The
+.Cm lib-depends-check
+will warn about it, but it is the only way to ensure that the port is
+rebuild when the library is updated.
+A comment in the Makefile about this expected warning should be added.
 .It "Warning: FULLPKGNAME-sub defined but not FULLPKGPATH-sub"
 .Ev FULLPKGNAME-sub
 has been explicitly defined by the port, instead of relying on the default,