While there isn't a single widely known "JKing" deep post, several possibilities exist depending on the context you're looking for:

Usually require more stability, often 42–48 inches deep.

In many areas, posts must be dug to at least 3 feet 6 inches, or even 4 feet, to reach below the frost line and prevent shifting. Specific Fence Types: Standard Line Posts: Typically require 36 inches of depth.

If you are looking for technical "deep post" advice related to construction (perhaps a specific brand or local jargon), general standards for setting posts deep include: