A bit of trivia: what does usr stand for?

[Bruce R. Montague]

Regarding:
 
> ... reference creat(2). ...
>
> I think it was Kerningham that said that given the chance
> to do it all over, he would have called it create(2).

I used (and "operated") IBM 1403 printers, teletypes, and 
various other impact printers of the same era, drum 
printers, band printers, etc.. The 1403 was arguably the
best, and most widely used, mainframe printer of them     
all. Output from other companies machines was often printed   
on 1403s (via tape transfer).

Invariably the print slugs that printed characters on all 
impact printers (and teletypes) wore out unevenly, 
reflecting frequency of character use. If used for normal 
text, the letter "e" was always the first to go (reflecting
its well-known English frequency). The highly-used
characters would start "fading" as their hammer/slug or
equivalent began to lose its sharp relief. This was not
a minor problem. An all-new print chain was like Christmas!

Band printers and chain printers, such as the 1403, had
multiple sets of the character set in their "chain". The
1403 chain allowed individual print slugs (characters)
to be replaced (handloaded) when they became worn. I
believe you could alter the frequency of the slugs to
match expected use by using the "control tape", although 
this didn't seem really commonly done. The 1403 chain
somewhat resembled a machine-gun ammo chain or bike chain.

Anyhow, programmers often tried to reduce the use of
common characters to avoid wearing out that character.
This sometimes was designed deeply into things. For
instance, the use of "." for the indirection operator in    
the BLISS language (equivalent to "*" in C, but much more
heavily used because all variables were "pointers") was
done for this reason (I heard Bill Wulf say once that's
why he did it).

So it is possible this common practice created a bias 
against "e" in Unix names.


 - bruce