> Oh.  On Linux, we get "[QZN]MAGIC" in the identification.  That's
> surprising--it almost seems like a failing on the part of /etc/magic.

oh, /usr/share/misc/magic (which is where it lives on NetBSD)
distinguishes the cases; it just says NetBSD/xxx "demand paged" or
"pure" or "", and "object file" or "executable" or what have you.

for instance, this is what it says for the x86 a.out formats:

0	belong&0377777777	041400413	NetBSD/i386 demand paged
>0	byte			&0x80		
>>20	lelong			<4096		shared library
>>20	lelong			=4096		dynamically linked executable
>>20	lelong			>4096		dynamically linked executable
>0	byte			^0x80		executable
>16	lelong			>0		not stripped
0	belong&0377777777	041400410	NetBSD/i386 pure
>0	byte			&0x80		dynamically linked executable
>0	byte			^0x80		executable
>16	lelong			>0		not stripped
0	belong&0377777777	041400407	NetBSD/i386
>0	byte			&0x80		dynamically linked executable
>0	byte			^0x80
>>0	byte			&0x40		position independent
>>20	lelong			!0		executable
>>20	lelong			=0		object file
>16	lelong			>0		not stripped
0	belong&0377777777	041400507	NetBSD/i386 core
>12	string			>\0		from '%s'