1.\" $OpenBSD: scope.in,v 1.4 2017/07/04 14:53:26 schwarze Exp $ 2.Dd $Mdocdate: July 4 2017 $ 3.Dt SM-SCOPE 1 4.Os 5.Sh NAME 6.Nm Sm-scope 7.Nd scope of the spacing macro 8.Sh DESCRIPTION 9Using an abbreviated example from the 10.Xr ksh 1 11manual. 12.Pp 13Modifiers can be applied to the 14.Pf ${ Ns Ar name Ns } 15form of parameter substitution: 16.Bl -tag -width Ds 17.Sm off 18.It ${ Ar name No :- Ar word No } 19.Sm on 20If 21.Ar name 22is set and not 23.Dv NULL , 24it is substituted; otherwise, 25.Ar word 26is substituted. 27.El 28.Pp 29In the above modifiers, the 30.Ql \&: 31can be omitted, ... 32