You know very well that that's not what "explain it" means. If you think the process isn't a secret, then find a document detailing the entire process, with spe

You know very well that that's not what "explain it" means. If you think the process isn't a secret, then find a document detailing the entire process, with specifics, end to end. What happens in the extra screening? Is it the same throughout the country? What might vary in the process (YMMV, after all), etc. You have a purely anecdotal account of what can happen at an airport that isn't even staffed by the TSA (https://www.flysfo.com/about-sfo/safety-security https://www.flysfo.com/about-sfo/safety-security). What everyone else is looking for is a specific, detailed, transparent description of the entire process.