why different swapping modes on executables?

[Root Boy Jim]

In article <126505 at uunet.UU.NET> rbj at uunet.UU.NET (Root Boy Jim) writes:
>In article <573 at adpplz.UUCP> martin at adpplz.UUCP (Martin Golding) writes:
>
>>My impression is that the (original) version of the Magic Number was
>>the actual value to load into the PDP 11 MMU control register, to select
>>one or the other model.
>
>HAHAHAHA! It's even worse than that! The Magic Number was a JUMP
>(actually a branch) across the a.out header. A 407 executable
>had a seven word (14 byte) header, a 410, eight words, 411 nine...
>Sneaky, huh?
>-- 
>		[rbj at uunet 1] stty sane
>		unknown mode: sane

I suppose this is one for the computer folklore file.
In my mailbox this morning was the following message:

	From dmr at research.att.com Wed Mar 27 01:49:38 1991
	From: dmr at research.att.com
	Date: Wed, 27 Mar 91 01:49:26 EST
	To: rbj at uunet.UU.NET
	Subject: 407 [netnews]

 	> HAHAHAHA! It's even worse than that! The Magic Number was a JUMP
 	> (actually a branch) across the a.out header. A 407 executable
 	> had a seven word (14 byte) header, a 410, eight words, 411 nine...
 	> Sneaky, huh?

	Nonsense.

        	Dennis Ritchie

Perhaps this was actually considered at one time but cooler heads prevailed?
I'm sure many people would be delighted with an elaboration.

-- 
		[rbj at uunet 1] stty sane
		unknown mode: sane