How this board works
Every board is one long list of conversations. A new topic starts at the left margin; replies are indented underneath whatever they reply to, so you can follow an argument down a branch without losing the rest of the page.
Each line shows the subject, who wrote it, and when. Click a subject to read the post and reply to it. A post marked (n/t) has no text beyond its subject line — the subject is the message.
Conversations are listed by their most recent activity: reply to a thread, even an old one, and it jumps back to the top of the board, still showing its original date. So the liveliest conversations are always the ones you see first.
Being told when someone answers
When you write a post there are two boxes under the message:
- when someone replies to this post — only direct answers to what you just wrote.
- when there is any new post in this thread — everything that follows, wherever it hangs in the conversation.
Both start empty every time, and empty means no email. Nothing is remembered between posts: if you want to hear about a thread, say so each time you write in it. That is deliberate — it is the only arrangement in which you cannot end up subscribed to something you never asked for.
Every notification carries a link that stops it, and that link needs no password: one click and the board is quiet about that post. You can also see everything you have asked for, and switch any of it off, on your account page.
A few details worth knowing. The board never emails you about your own posts. If you ticked both boxes and a reply matches both, you get one email, not two. Notifications only go to a confirmed address. And on a members-only board the email tells you there is a new reply and links to it, but does not include the message itself — what is written behind a locked door stays there.
Times
Every time on the board is shown in your own time zone, whatever it is and wherever you are. There is nothing to set: your browser tells the page, and it follows you if you travel.
Underneath, the board keeps every time in UTC, and hovering over any timestamp shows you that UTC value. This matters on a board where people quote times at each other: if two members disagree about when something was posted, there is one absolute answer either of them can check.
Two exceptions, both on purpose. The moderators' pages stay in UTC, because they are the board's formal records and a record needs one fixed clock. And the per-day plots on the statistics board count UTC days, since that is how the figures were tallied in the first place.
With scripting switched off, times appear in UTC instead. Nothing breaks; the conversion is the only thing lost.
The recent-posts panel
Under the board list in the menu is Recent posts: the conversations with the newest activity across every board you can read, whichever board you happen to be looking at. It is how you notice that something has started up on a board you had no reason to open.
Entries with posts you have not read yet are bright; ones you are caught up on fade back, so the eye lands on what is new. The board each conversation lives in is named in brackets underneath it. Your own posts never count as unread to you. On a phone the panel folds away behind its heading — tap it to open it.
Pasted links
Paste a web address on its own and the board shows the page's own headline in place of the address, with the site's name beside it in brackets:
Mortgage rates climb for fourth-straight week (cnn.com)
The board reads the page's title itself, once, in the background after your post is saved — so posting is never held up by a slow site, and your browser never touches the page until you click it. The site being read sees a request from this board's server, not from you; no cookies are sent, nothing but the title is kept, and pictures and scripts on that page are never fetched. If the title cannot be read the link simply stays as you typed it. The domain is always shown, so a link wearing a headline can never hide where it actually goes.
A few domains are not carried here at all. Link to one and your post will be refused when you send it, naming the domain, so you can take it out and post again — nothing you wrote is altered behind your back. Moderators keep that list and can show you what is on it.
Finding things again
The box at the top of the menu searches every post on every board you can read, and it searches two ways at once.
By word. Type words and it finds the posts containing them. Put a phrase in "quotes" to keep the words together, put a minus in front of a word to leave those posts out, and end a word with * to match anything starting with it — launch* finds launched and launching.
By meaning. If you cannot remember the words — and half the time nobody can — describe the post instead, in your own words, as you would to a person: that thread about meat grown in a laboratory. The board compares what you meant against what every post means, so it can find the right thread even when your description and the post share no words at all. A post that literally contains what you typed still comes first; the rest are offered underneath as “is it one of these?”
Either way you can narrow the search with the filters under the box: only posts with a link, only posts with a picture, by one member, between two dates, or only threads that got at least so many replies. That combination — a vague memory plus “it had a link, and it was about a year ago” — is usually enough to find something you had otherwise given up on.
If you are signed in, the board also keeps track of what you have already seen, and colours each subject accordingly:
| Colour | Means |
|---|---|
| gold, with a small arrow | new since your last visit |
| blue | you have not opened it yet |
| purple | you have opened it |
| red | a moderator marked it urgent |
Posts written since your last visit are gold, and the conversation carries a count of them; looking at a board page counts as having seen the conversations on it, so the gold clears on your next visit. A subject turns from blue to purple when you open the post — and because the board remembers this itself rather than leaving it to your browser, it looks the same whether you read on your computer or your phone. Mark all read in the menu marks everything read at once.
Changing a post
You can edit anything you have written, at any time — there is no deadline. Open the post and press edit.
An edited post carries a small edited note with the date, and that note is a link: anyone can follow it and read every earlier version, with who changed it and when. Nothing is quietly rewritten, and nothing is lost. This is not there because anyone is expected to misbehave; it is there so that if the question ever comes up, it is answered in five seconds instead of in an argument.
Posts in a thread a moderator has locked can no longer be edited by their authors. Moderators can edit any post, and doing so is written to the moderator log as well as the post's own history.
Deleting a post
Open your post and press delete. What happens next depends on whether anyone has answered you.
If nobody has replied, the post disappears completely — text, pictures, earlier versions, the lot.
If somebody has replied, the line stays in the thread reading ---DELETED BY USER---, and everything you wrote is removed from it. Their replies are not touched. Those are other people's writing, and a conversation that quietly loses its middle is one nobody can follow afterwards.
Deleting is not the same as editing. An edit keeps the earlier version where anyone can read it; a deletion removes the words from the board altogether, and no moderator or administrator can put them back. The board asks you to confirm for that reason. If you only want to change what a post says, edit it instead.
Your own page
Every member has a page of their own. My page in the menu, under your name, opens yours; Members lists everyone else's. The top of the page shows your name and the day you joined, and the rest is yours to write.
It is written exactly like a post — the same buttons, the same bracket tags, the same equation editor — so anything that works in a post works here. Say what you work on, what you are looking at, where you are writing from, or nothing at all; a page is optional and an empty one is nobody's business.
Pictures and files. You can put up to 10 files on your page, 10 MB each and 50 MB altogether. Pictures go into the text where you put them, with the same [pic1] markers a post uses — there is a button for each one under the message box. Documents are listed at the bottom of your page for other members to download.
Which documents. PDF, and the modern Word, Excel and PowerPoint formats — .docx, .xlsx, .pptx — plus plain text, CSV and rich text.
The old Office formats (.doc, .xls, .ppt) are not accepted, and neither is any file containing macros, whatever it has been named. Those are how Office documents carry viruses, and the modern formats cannot. If a file of yours is refused, open it and use Save As to save a copy in the newer format — that copy will go on fine.
Pages are shown to signed-in members only, and so is the list of members and every file on a page. Posts here are public because they are about spaceflight; a page is about a person, and that is a different thing. Even so, remember that "members only" means every member: write what you would say to the board, not what you would tell one person.
Downloading a file from someone's page saves it to your computer rather than opening it here. Treat a document from a member exactly as you would treat one attached to an email — the board checks that a file really is the sort of file it claims to be, but it cannot know what is inside it.
Posting
You need an account to post. Register with a username, an email address and a password; you will be sent a link by email to confirm the address before your first post. Reading requires no account at all.
Pictures
Three ways to put a picture in a post. Paste it — take a screenshot or copy an image on your computer and press Ctrl-V (Cmd-V on a Mac) in the message box, and it uploads. Drag it — drop an image file straight onto the message box. Or use the Pictures box on the posting form to pick one from your computer or phone. However it arrives, it appears under your message with a thumbnail and an insert here button, and readers can click it to see it full size.
There is also a fourth way for a picture already on the web: paste its web address, and if it ends in .jpg, .png, .gif or .webp it shows in your post as the picture itself — loaded from where it lives, not copied here.
Pictures you upload are shrunk to a sensible size automatically, and the location data your phone camera records is stripped off before anything is stored.
Putting a picture in a particular place. Once you have chosen your pictures, each one appears under the message box with an insert here button. Put the cursor where you want the picture, choose a size, and press it — a marker like [pic1 large] goes into your message and the picture appears exactly there. Pictures you do not place stay in a strip under the message, as before.
| To get | Type |
|---|---|
| your first picture, medium | [pic1] |
| your second picture, large | [pic2 large] |
| small, with the text wrapping to the left of it | [pic1 small right] |
| as wide as the column | [pic1 full] |
Full resolution. The sizes above are how big the picture appears in the post. Separately, one picture per post may be kept at its original resolution — tick keep at full resolution under it before posting. The post still shows the ordinary web-sized copy, so nobody reading on a phone downloads the whole large file by accident; clicking the picture opens the full one. Use it for the photograph that is worth looking at closely — up to 10 MB.
Sizes are small, medium, large and full; wrapping is left or right. On a phone every picture goes on its own line, because there is not enough width to wrap text around one.
Sharing a file
Posts carry text and pictures. To share a document — a PDF, a spreadsheet, a paper — put it on your own page (there is a files section on it) and link people to your page from your post. That keeps every download in one place, yours, where you can see and remove what you have shared.
Your signature
A few lines that appear under every post you write — a name, what you do, a favourite line. Write it on My page, under Your signature.
It is not fixed to the post: change your signature and it changes under everything you have ever written. There is a switch to turn it off without deleting it.
Up to 300 characters and 4 lines, and text up to 14pt rather than the 40pt of a message — it is under every post you write, and a large one wears out its welcome quickly.
The Font button lives here, and only here. You can set your signature in any of thirteen typefaces, which is exactly the sort of small individuality a signature is for; posts stay in one face because a board where every message looks different stops being quick to read, and being quick to read is what this format is good at.
A picture in it. You can upload one small picture — up to 200 by 60 pixels — and write [sigpic] where you want it. Note that this one is public, unlike the pictures on the rest of your page: it appears under your posts, and the boards can be read by anyone.
Equations
Press Math above the message box. A panel opens with a line to type in, a palette of the usual pieces — fractions, roots, integrals, sums, Greek letters — and a preview that redraws as you type. Press Insert equation and it drops into your message.
What you type is LaTeX, the notation used in physics and astronomy papers. If you already know it, type it; if you do not, the palette buttons write it for you and you can edit what they produce.
| To get | Type |
|---|---|
| an equation in a sentence | [math]E = mc^2[/math] |
| one on its own line, centred | [math display]int_0^infty e^{-x^2}dx[/math] |
| a fraction | rac{a}{b} |
| a power, a subscript | x^{2}, x_{i} |
| a square root | sqrt{x} |
| Greek letters | alpha, lambda, Omega |
Equations are drawn by the board itself, not by anything your browser has to download, and they can be copied out as their original notation. An equation may be up to 2,000 characters.
Preview
The Preview button above the message box shows the post exactly as it will appear — pictures where you put them, equations drawn, links live. Press it again to close it. It is the same code that draws the finished post, so what you see there is what everyone else sees.
Formatting
The buttons above the message box do all of this for you — select some words and press one. If you would rather type it, the tags are:
| To get | Type |
|---|---|
| bold | [b]bold[/b] |
| italic | [i]italic[/i] |
| underlined | [u]underlined[/u] |
| a link on chosen words | [url=https://example.com]these words[/url] |
| a picture from the web | [img]https://example.com/photo.jpg[/img] |
| a video | [video]https://www.youtube.com/watch?v=…[/video] |
| an equation | [math]E = mc^2[/math] |
| one of your own pictures | [pic1 large] |
| a quotation | [quote]their words[/quote] |
| bigger or smaller words | [size=24]words[/size] |
| coloured words | [color=gold]words[/color] |
Size, colour and emoji
Select some words and press Size or Colour. Sizes run from 8 to 40, which is as large as the board goes; anything larger you ask for comes out at 40. The colours are a fixed set of thirteen, all chosen to be readable against the dark page — there is deliberately no way to write your own, because the first thing somebody does with that is make their text the same colour as the background.
You can colour or size a single word or a whole paragraph — select as much as you like and press the button. If you forget the closing tag, nothing happens and you simply see the tag as you typed it, rather than the rest of your post changing colour; press Preview if you are not sure it came out right.
Emoji. Press the 😀 button for a panel of them, grouped, with the ones you have used recently at the top. You can also paste any emoji straight in, or use your computer's own picker — Windows key and full stop on Windows, Control-Command-Space on a Mac.
How an emoji looks is decided by your computer, not by the board, so a very old machine may show a box instead of a picture for the newer ones. The familiar ones work everywhere.
A web address typed on its own becomes a link with no tags needed, and one ending in .jpg, .png, .gif or .webp shows as the picture itself.
Video embeds from YouTube and Vimeo, or from a direct link to a video file. Anything else becomes an ordinary link — the board will not run a player from a site it does not recognise.
Moderators
Moderators can remove posts, lock threads and suspend accounts. If something needs their attention, say so on the Community board.
They can also mark a post urgent, which shows its subject in red on the board. That is the board's staff saying read this — a notice, a warning, something that affects everyone — and it means something only because it is rare. Members cannot set it on their own posts.
Cookies, and what is kept
This board sets two cookies. Both are its own; there are no third-party cookies, no advertising cookies, and nothing from an analytics company. The whole list is short enough to print here.
| Name | What it is for | How long |
|---|---|---|
| sid | Keeps you signed in. It holds a random session number and nothing else — no name, no address, no password — signed so a forged one is refused. Set when you log in, deleted when you log out. | 30 days |
| hzv | Counts visitors. A random number with no meaning, so that one person reading ten pages is counted as one visitor for the day rather than ten. It is not connected to your account, your name or your address, and the board never links it to the cookie above. | 1 year |
Both are marked HttpOnly, so the page's own scripts cannot read them, and SameSite, so they are not sent when you arrive from another site.
Two more things are remembered inside your browser only and are never sent to the server: the emoji you used most recently, so the picker can put them first, and whether the menu is open or shut on a small screen. Clearing your browser's data forgets both, and nothing here depends on them.
What is deliberately not recorded matters as much as what is. Your address is not written down: that is off by default, and when a moderator does turn it on for an incident it is written in a form that cannot be turned back into an address without a key kept outside the database, and it expires by itself. Videos are embedded through YouTube's no-cookie domain, so YouTube sets nothing on you unless you actually press play. There is no tracking pixel and no fingerprinting anywhere on this board.
Some of this is a nuisance to implement and none of it is required of us. It is here because a discussion board is a place people should be able to read without being measured.