There is this:
(Red Hat Enterprise Linux)
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Then there is this:
(RedHatEnterpriseLinux - this one happens to be part of Chapter 1's title)
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Then there is A LOT of this (throughout the RH124 lessons -- I haven't looked at RH134 yet):
(RedHat EnterpriseLinux)
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There may be others...
I'm not trying to be picky; this is about the brand. It really is important to be consistent - it shows attention to detail.
Looking at the official documentation and the web site (which can be found in links at the bottom of many lesson pages), it probably should be the first one - four words, separated by spaces:
Red Hat Enterprise Linux
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My 2c
Red Hat
Learning Community
A collaborative learning environment, enabling open source skill development.