What does a verification mark actually tell me?

What was checked, who checked it, against which standard, when, and when it stops being current. If any of those is missing, it is a badge rather than a verification.

The full explanation, including who awards which half of the score and why the report is published, is on the verification page.

The audit report behind any mark is public, free, and at its own address. Including whatever was not awarded and the reason for it.

If this did not answer it: support inside your account is under development, and until it opens, this says what does reach a person.