diff --git a/bin/ps/ps.1 b/bin/ps/ps.1
--- a/bin/ps/ps.1
+++ b/bin/ps/ps.1
@@ -138,10 +138,15 @@
 .Fl O
 .Pc .
 The individual columns requested via a canned display option which have the same
-keyword as that of some column added by earlier options are not added again.
-This kind of automatic removal of duplicate keywords in canned displays is
-useful for slightly tweaking these displays without having to rebuild variants
-from scratch, e.g., using
+keyword as that of some column added by an earlier canned display option, or that
+explicitly specified through
+.Fl O
+or
+.Fl o
+anywhere on the command line are suppressed.
+This automatic removal of duplicate keywords in canned displays is useful for
+slightly tweaking these displays and/or combining multiple ones without having
+to rebuild variants from scratch, e.g., using only
 .Fl o
 options.
 .Pp
@@ -1012,14 +1017,6 @@
 Finally, columns requested through multiple occurences are not grouped together,
 as one may naturally expect.
 .Pp
-Automatic removal of duplicate columns from canned displays only works backwards
-at time of insertion, i.e., adding a new canned display will lead to checking
-columns before it but not those after it.
-Besides the inconsistency, this prevents relocating columns of canned displays
-further right, which can be useful, e.g., to relocate a column with the
-.Cm command
-keyword at end of display.
-.Pp
 The
 .Fl a
 option has no effect if other options affecting the selection of processes are