Rev 1:8: Why is 'legei Kurios' not in the critical apparatus of UBS5, as a variant of 'legei Kurios o Theos'?

Question

Background: Today I bought a UBS5 Greek New Testament. As I looked up Revelation 1:8, I noticed that the critical apparatus doesn't include the variant 'legei Kurios' (in stead of 'legei Kurios o Theos', as the critical text reads).

However, this variant, 'legei Kurios' (without o Theos), was used for the King James Version, and all other major translations which were based on Erasmus' Greek text etc. To me, this seems enough reason to include it in the critical apparatus.

Because of this, I've started to question the reliability of the critical apparatus. Therefore I'm considering sending the UBS5 back to the shop (and perhaps buying an NA28 instead).

Before I do that, I would like to know the following...

Main question: Can anyone explain to me why 'legei Kurios' (without 'o Theos') is not in the critical apparatus of Rev 1:8 in UBS5? (In other words: is it reasonable that they left it out?)

Subquestions:

1. What manuscripts (and other sources) support omitting 'o Theos'?
2. The Tischendorf critical text does mention the variant: However, I don't know how to interpret it. What does 'o Kurios cum 30.?' mean?
3. Does the NA28 include the variant? (Then I might consider buying that one instead). Edit: I now know the NA28 does not include it.

Any other suggestions are welcome too. P.S. I already read the somewhat similar question about the passage at Who is speaking in Revelation 1:8? But I don't think that answers my question.

Thanks in advance!

Answer 1

ϛ means the edition by Stephanus of 1550. “cum 30.?” means that Tischendorf is guessing that Stephanus found this reading in the miniscule manuscript “30”, but is not able to check the manuscript himself. The upshot is that the shorter version of the sentence is not in any of the old manuscripts or ancient citations.