Do XPG4 and POSIX agree on this?

source@NetBSD.ORG writes:
> kleink
> Mon Jan 12 08:05:41 PST 1998
> Update of /cvsroot/src/include
> In directory netbsd1:/var/slash-tmp/cvs-serv15982/include
> 
> Modified Files:
> 	string.h unistd.h 
> Log Message:
> Per XPG4, move the prototype of swab() from <string.h> to <unistd.h>.
> 
> 
> kleink
> Mon Jan 12 08:05:43 PST 1998
> Update of /cvsroot/src/lib/libc/string
> In directory netbsd1:/var/slash-tmp/cvs-serv15982/lib/libc/string
> 
> Modified Files:
> 	swab.3 swab.c 
> Log Message:
> Per XPG4, move the prototype of swab() from <string.h> to <unistd.h>.
>