From PostgreSQL wiki
It's very easy to edit the contents of a wiki. It only takes a few clicks.
- Click the edit page tab at the top of the page.
- Make changes to the text.
- Click the Save page button.
Simple as that!
Editing rules, editing conventions, and formatting
The number one rule of wiki editing, is to be bold. Dive in and make changes. Other people can correct mistakes later, so have confidence, and give it a try! There can be all kinds of editing conventions, rules, and philosophy governing the editing of wiki pages, but the "be bold" rule overrides these!
In general try to write clearly and concisely and make sure you are always aiming to do something which improves the wiki contents. An edit might be to contribute whole paragraphs or pages full of information, or it could be as simple as fixing a typo/spelling mistakes.
When you need to use some type of formatting e.g. new headings or bold text, you do this using wiki syntax, see Help:Formatting for some of the common types of formatting used.
Before you save a change, you can enter a short note in the Summary box describing your changes. Don't worry too much about this, or spend too much time thinking about it, but try to give a little description of what you just changed e.g. "fixed typo" or "added more information about sunflowers".
The summary gets stored alongside your edit, and allows people to track changes in the wiki more effectively.
It's a good idea to use the 'Show preview' button to see what your change will look like, before you save it. This is also related to tracking changes because every time you save, this is displayed to others as a separate change. This isn't something to worry about too much, but it's good to get into the habit of eliminating mistakes in your own work, by using a preview before saving, rather than saving several minor corrections afterwards.
Other types of editing
With wiki edits you can start a new page, move (or rename) a page, or even delete a page:
Remember you should always aim to improve the overall contents of the wiki with your edits.
Every article has its own "talk page" where you can ask questions, make suggestions, or discuss corrections. See Help:Talk pages