diff --git a/bin/ps/ps.1 b/bin/ps/ps.1
--- a/bin/ps/ps.1
+++ b/bin/ps/ps.1
@@ -122,10 +122,8 @@
 .Fl o
 and
 .Fl O
-options, which add columns with data corresponding to the passed keywords, and
-for
-.Fl O
-possibly the columns of the default display, as well as combinations of the
+options, which add columns with data corresponding to the passed keywords, as
+well as combinations of the
 .Fl j , l , u ,
 and
 .Fl v
@@ -317,15 +315,15 @@
 Extract the name list from the specified system instead of the default,
 which is the kernel image the system has booted from.
 .It Fl O
-On first occurence, add all columns of the default display
-.Po
-as if by
-.Fl o
-.Pc
-and insert just after the process ID column in that default display the columns
-associated with the passed space- or comma-separated list of keywords.
-On next occurences, just insert the keywords of the passed list, as if by
-.Fl o .
+Save passed columns in a separate list that in the end is grafted just after the
+display's first occurence of the process ID column as specified by other
+options, or the default display if there is none.
+If the display prepared by other options does not include a process ID column,
+the list is inserted at start of the display.
+Further occurences of
+.Fl O
+append to the to-be-grafted list of columns.
+This option takes a space- or comma-separated list of keywords.
 The last keyword in the list may be appended with an equals sign
 .Pq Ql =
 as explained for option
@@ -1008,15 +1006,6 @@
 For all these reasons, the behavior is expected to be changed soon to using the
 effective user ID instead.
 .Pp
-Option
-.Fl O
-has not been designed to be combined with other options as it forces insertion
-of the default display on first occurence.
-Moreover, these default display's columns are then not considered for duplicate
-elimination, contrary to those of canned displays.
-Finally, columns requested through multiple occurences are not grouped together,
-as one may naturally expect.
-.Pp
 The
 .Fl a
 option has no effect if other options affecting the selection of processes are