How to send and format a message
Enter sends, Shift and Enter makes a new line, and the row above the box handles bold, lists, quotes and code.
The composer sits at the foot of every channel and thread, reading "Message… (type @ to tag anything)". This page covers writing in it. See What is chat? for how channels are laid out.
How do you send?
Enter sends. Shift+Enter makes a new line without sending.
On a phone the on-screen keyboard's return key inserts a line break, so use the coral send button instead.
Your message appears immediately, dimmed, while it goes. It firms up once it lands, and says so plainly if it does not.
How do you avoid sending half a message?
Compose with Shift+Enter for every line break and press Enter only when you are finished.
Inside a list, a quote or a code block, Enter continues that block rather than sending, so a bulleted list behaves the way you would expect.
There is one habit worth forming: the composer keeps nothing if you navigate away, so finish a long message before you go and look something up.
What formatting is there?
The row above the box: Bold, Italic, Strikethrough, Link, Bulleted list, Numbered list, Quote, Inline code and Code block. Each highlights when it is active.
Formatting is stored in a plain-text style that other tools can read, which is what keeps a copied message legible somewhere else.
Use code formatting for anything a person will retype: a SKU, a PO number, a formula. Inline code for a fragment and a code block for several lines.
How do you add a link?
Click the link button and paste the URL. It has to start with http:// or https://.
What is worth knowing about messages on a phone?
Formatting is a web feature. Bold text sent from the web reads as literal asterisks in the iPhone app, so for anything the phone-carrying half of your team must read, plain sentences travel better than heavy formatting.
How long can a message be?
Up to 4,000 characters, which is several screens of text.
There is no counter, so if a very long message refuses to send, its length is the first thing to check. In practice anything approaching that limit is better as a document, per What are documents?.
How do you fix a message you got wrong?
Delete it and post again. Hover your own message and click the red bin.
There is no confirmation step, so read the message before you click. It disappears for everyone immediately.
Two things survive a delete, deliberately. Replies to it remain, showing that the original is unavailable. And anything created from it, such as a task or a decision, is untouched, per How to turn a conversation into work.
The bin appears only on your own messages.
What else can go in a message?
Tags, which turn people, tasks, documents, products and customers into live chips. See How to tag people, tasks, documents and products.
And files, from the paperclip. See How to share files and photos in chat.