... four-digit PIN ...

Note this from the entry. I can't be more specific. There's not a one-size-fits-all answer.

Instead, pay close attention to legal definitions, which vary by jurisdiction, and the wording of criminal charges or convictions. Consider the nuance of each situation and what may be conveyed or perceived by the language used.

I've never heard of the former. Maybe it's a regional difference.

It's the variant of the coronavirus.
Here's the relevant section of our Coronavirus Topical Guide:

virus variant (revised)

Viruses often develop small changes, or mutations, as they reproduce. Some are harmless but others are more worrisome, especially if they make the virus more contagious or make people sicker. They also might curb the effectiveness of some treatments or vaccines. Use variant or version to describe a new form of a virus in general. Following guidance from the World Health Organization, refer to specific variants by letters of the Greek alphabet as assigned by WHO and include a brief reference to where the variant was first seen. For example: The latest outbreak was linked to the alpha variant, first detected in the United Kingdom. On later references, the alpha variant, or simply the variant if only one is referred to in the story. Avoid using the numbers given to variants, such as B.1.1.7 for the one first found in the U.K. Avoid using country labels like the South Africa variant.

Variants identified by WHO: alpha (first detected in the U.K.); beta (first detected in South Africa); gamma (first detected in Brazil); delta (first detected in India); epsilon (first detected in the U.S.); zeta (first detected in Brazil); eta (first detected in multiple countries); theta (first detected in the Philippines); iota (first detected in the U.S.); kappa (first detected in India). For a new variant that hasn't yet been named by the WHO, use phrasing such as the latest variant of concern, first seen in Iowa in May 2021 ...

If a variant is different enough in certain ways than previous ones, it might be designated as a new strain or lineage, but these are not interchangeable terms.

We generally don't use the name unless the woman has granted specific permission. See more details in the full entry.

Our style is the lowercase: the delta variant.

Generally, yes. It could depend on the construction of a specific sentence.

No hyphens in any dual heritage term.

No hyphen. Capital gains, like real estate and chocolate chip, is easily recognizable and understood without the hyphen as a modifier.

No situation comes to mind in which we would put quotes around the names of fictional characters. 

An Emmy-nominated actor. She is an Emmy nominee. She is an Emmy winner. Emmy winner Jodie Comer.

We would probably go along with the way most specialty publications use it -- and would set a style when it comes into common usage.

 It's co-branded. I've deleted the 2011 response.

If this is the name of an event -- and it seems to be -- you probably should go along however the organizers spell it.  

Our inclination is your inclination. Unless punctuation clarifies, we generally avoid it. And this case, there's no confusion.

It isn't wrong, but it is redundant. We'd probably do it this way: If you need help finding the perfect pace to meet your distance goal, contact one of our coaches.

I'm not sure how it would be superapp in AP style. We'd go with two words, and an explanation.

Either is fine. I'd go with government program leaders.

Putting quote marks around real could give the impression to some readers that you are taking the description lightly or insincerely. I'd do it without the quote marks.
You wouldn't write the "tall" Caleb or the "smart" Caleb, right?

We would avoid such a construction. There must be a way you can recast the sentence. If for some reason you have to start the sentence with it, you might sneak it in as a distant cousin of the years or letter/number exceptions we note. That's certainly better than spelling out twenty-four/seven.

AT THE START OF A SENTENCE: In general, spell out numbers at the start of a sentence: Forty years was a long time to wait. Fifteen to 20 cars were involved in the accident. An exception is years: 1992 was a very good year. Another exception: Numeral(s) and letter(s) combinations: 401(k) plans are offered. 4K TVs are flying off the shelves. 3D movies are drawing more fans.

No need to do so. Just use the shortened form on later references.

12 x 6 x 12 inches

We use standard capitalization. You would need to decide if you want to abide by the request, or use standard style. Regardless of which way you go, you can include wording such as: She styles her name with all lowercase letters: joan smith.

Since oncology is just a speciality within the field of medicine: oncology Dr. Ned Mancuso.