===================================================================
RCS file: /cvs/mandoc/regress/roff/esc/o.in,v
retrieving revision 1.2
retrieving revision 1.3
diff -u -p -r1.2 -r1.3
--- mandoc/regress/roff/esc/o.in	2017/07/04 15:26:34	1.2
+++ mandoc/regress/roff/esc/o.in	2022/06/08 13:24:02	1.3
@@ -1,5 +1,5 @@
-.\" $OpenBSD: o.in,v 1.2 2017/07/04 15:26:34 schwarze Exp $
-.Dd $Mdocdate: July 4 2017 $
+.\" $OpenBSD: o.in,v 1.3 2022/06/08 13:24:02 schwarze Exp $
+.Dd $Mdocdate: June 8 2022 $
 .Dt ESC-O 1
 .Os
 .Sh NAME
@@ -17,3 +17,39 @@ narrow/wide: x\o'|O'x
 wide/narrow/narrow: x\o'O-|'x
 .br
 narrow/narrow/wide: x\o'|-O'x
+.Ss Argument delimiters
+unsupported \er: \o\rxy\ru
+.br
+ignored \e&: \o\&xy\&u
+.br
+useless \e.: \o\.xy.u
+.br
+invalid \eG: \o\GxyGu
+.br
+special \e-: \o\-xy\-u
+.br
+break \ep: \o\pxy\pu
+.br
+nospace \ec: \o\cxy\cu
+.\".br
+.\"XXX skipchar \ec: \o\zxy\zu
+.br
+.ds mystr zx
+string expansion: \o\*[mystr]yzu
+.br
+.nr myreg 12
+register expansion: \o\n[myreg]31u
+.br
+ignored \eON: \o\O1xy\O2u
+.br
+special character: \o\(hyxy\(hyu
+.br
+ignored \eZ\(aqstr\(aq: \o\Z'foo'xy\Z'bar'u
+.br
+horizontal motion: \o\h'1'xy\h'3'u
+.br
+horizontal line: \o\l'4'xy\l'2'u
+.br
+overstrike: \o\o'ab'xy\o'cd'u
+.br
+unterminated: \o'xy