Privacy Policy

The short version

This site is a stack of static files. There is no account to create, no comment box, no newsletter, no contact form and no analytics script — I genuinely do not know who reads which page, and I have not built myself any way to find out. The one thing on these pages that is not mine is Google's advertising code, which pays for the hosting, and which does set cookies. That is what most of this page is about, and the section below tells you exactly how to switch it off.

What I collect from you directly

Nothing. Reading this site does not create a record with my name on it. There is no sign-in, so there is no profile; no comment form, so there is nothing of yours stored; no mailing list, so your address is never asked for. Reading a chapter does not mark it as read anywhere but in your own browser, and the language you pick is simply a different URL rather than a preference I keep about you.

If you email me, then I have your email — that is unavoidable and it is the point. What you send sits in my mailbox for as long as it is useful to answer you, it is used to answer you and nothing else, and it is never added to any list. That is covered further down under who is responsible.

Server logs

The pages are served by a hosting provider rather than a machine in my flat, and like every web server on the internet theirs writes an access log: the IP address a request came from, the time, the page asked for, the browser's user-agent string, and whether the request succeeded. This happens for technical reasons — serving traffic, absorbing abuse, noticing an outage — and it happens before any of my code runs.

Those logs are the provider's, kept for a short period on their own retention schedule and then discarded. I do not pull them into anything, do not join them to anything else, and do not use them to work out who you are.

Cookies

I set no cookies of my own. This site has nothing to remember about you between visits, so it asks your browser to store nothing — no session cookie, no preference cookie, no first-party analytics identifier.

The cookies that do get set here come from the advertising described next, and they are set by Google and its advertising partners rather than by me. Your browser is where they live and your browser is where you can see them, block them or delete them, in whatever it calls its privacy or site-data settings. Blocking them does not break this site; nothing here depends on a cookie to work.

Advertising

This site takes part in Google AdSense, an advertising program run by Google, and that is what pays for it. To make it work, every page loads a script from Google, and once loaded that script operates under Google's rules rather than mine. The disclosures below are the ones Google requires publishers to make, and they describe what actually happens.

• Third-party vendors, including Google, use cookies to serve ads based on your prior visits to this website or to other websites.
• Google's use of advertising cookies enables it and its partners to serve ads to you based on your visit to this site and/or other sites on the internet.
• You can opt out of personalised advertising by visiting Google Ad Settings. Ads keep appearing after you do — they simply stop being chosen from your browsing history.
• Where other ad networks appear here alongside Google, they operate under their own privacy policies, and the industry opt-out pages listed below cover them in one go.

What that code receives is the ordinary technical context of a web request — your IP address, your user-agent, the page the ad is sitting on, your approximate location as inferred from the address, and whatever its own cookies already say about browsing it has seen elsewhere. It uses that to choose an ad, count that the ad was shown, and detect click fraud. Google's own account of it is in its advertising technologies notice and its privacy policy, and those govern it, not this page.

What Google does not get from me is anything else, because I have nothing else to give it. I pass it no email address, no name and no identifier of my own; I do not upload audience lists; and because I run no analytics, there is no reading history on my side that could be joined to an ad profile even in principle.

Turning it off

Three routes, in rough order of how thoroughly they work:

• Google's own switch — Google Ad Settings turns personalisation off for Google's ads wherever you meet them.
• The industry opt-out pages, which cover many networks at once: aboutads.info, the NAI opt-out, and Your Online Choices for Europe. Note that these record your choice in a cookie, so clearing your cookies clears the opt-out with them.
• Your browser or a blocker — refusing third-party cookies, or blocking the ad script outright, stops it at your end and needs nobody's cooperation. I would rather you read the site with a blocker on than not read it, and nothing here is gated behind letting ads through.

If you are in Europe or the UK

Personalised advertising there needs your consent rather than your silence. Where that applies, Google's advertising code is required to gather that choice through a consent interface before it can set an advertising cookie or use one, and to keep showing you non-personalised ads if you decline. If you are shown such a prompt on this site, that is what it is for, and it is the mechanism through which your answer takes effect — declining is a real option and it costs you nothing here.

The legal basis for the rest is narrow. Serving you the page you asked for is my legitimate interest in running a website at all, and so is the server log that comes with it. Advertising rests on the consent described above, wherever consent is what the law requires.

What this site deliberately does not do

Some of these are the things a site like this usually does, so it is worth being specific about their absence:

• No analytics. No Google Analytics, no Plausible, no Fathom, no hosted counter of any kind. Page-view numbers would be nice to have and are not worth what collecting them costs you.
• No fonts loaded from someone else. The typeface is downloaded when the site is built and served from this domain, so reading a page sends no request to a font CDN.
• No embeds. No YouTube players, no tweets, no comment widget, no like buttons, no chat bubble — each of those is a tracker that arrives with the content, and this site has none of them.
• No fingerprinting, no session recording, no heatmaps, and no advertising pixel belonging to a social network.
• Nothing is sold. I have no data about you to sell, and would not be in this business if I did.

Links to other sites

Articles and chapters here link out constantly — to documentation, to source repositories, to other people's writing. Following one takes you somewhere with its own privacy policy and its own idea of what to record, and I have no control over and no responsibility for what happens once you arrive. The same is true of an ad: clicking it hands you to an advertiser I have never met and cannot vouch for.

Children

This site is written for people who write software, not for children, and I don't knowingly collect anything from a child under 13 — or under the higher age your country sets. Since there is no sign-up and no form here, there is nothing for a child to submit in the first place.

Who is responsible for this

This site is mine — the work of one independent developer in Hanoi, Vietnam. I decide what it does, which in the language of data protection law makes me the controller for everything described here, with the exception of the advertising: for the data its own code collects, Google acts on its own behalf and answers for it under its own policy.

Write to me at admin@tuanem.com about any of it. The contact page says what else that address is good for.

Your rights

Depending on where you live you may have the right to ask for a copy of what is held about you, to have it corrected or deleted, to withdraw a consent you gave earlier, or to object to a particular use. You are welcome to ask me, at the address above, and I answer as fast as I can and within a month at the outside, free of charge.

Be warned that my honest answer will usually be that I hold nothing — which is the point of building the site this way, but is a frustrating reply if you were expecting a file. For anything the advertising collected, Google holds it and Google's privacy policy is where those requests go; the ad settings page linked above is the fastest route to what it has attached to your browser.

If you think I have handled something badly, tell me first — it is usually a misunderstanding I can fix the same day. You are also entitled to complain to the data-protection authority for the country you live in without going through me at all.

Changes

When this policy changes I update this page and the date below. If I ever add something that collects more than what is described here — an analytics script, a comment system, a mailing list — this page says so before it goes live, not after.