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From: Lawrence D'Oliveiro <ldo@nz.invalid>
Newsgroups: comp.os.vms
Subject: System UICs
Date: Fri, 7 Jun 2024 02:32:43 -0000 (UTC)
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As I recall, on VMS, SYSPRV privilege was effectively granted to any 
process whose UIC was in a “system” group. By default this was all UICs 
from [1,*] to [10,*] (octal), but I recall docs saying the upper limit was 
configurable.

I also recall that, when you woke up the login prompt, the LOGINOUT 
process was created running under UIC [10,40]. I wonder if this was chosen 
to ensure that sysadmins would never lower the upper bound below 10 octal, 
they could only raise it? Did the UIC [10,40] have any other significance? 
Perhaps something from RSX-11 days?