Notice

What this site is, what it is not, and how outside links are used.

A few plain statements about what this site is and is not.

General information only

These pages are study notes. They are not professional training, career advice or security advice for a production system. Test anything you learn here on your own machine with practice data.

Outside links

Links to other sites illustrate a point and are not endorsements. Some lead to pages in other languages and from unrelated industries, including gaming, and are cited as examples of page structure. Where that is the case the article says so.

Gambling

This is not a gambling site and it does not recommend gambling. Gambling is for adults only and is restricted or illegal in some places. If it is causing harm, seek help; in the United States the national helpline is 1-800-MY-RESET.

No accounts, no tracking of learners

There is no sign-up, no comment system and no course progress stored here.

Corrections

Each page shows its revision date. Errors are corrected when pages are revised.

// revised 2026-11-12 by Ilya Kessler