If you find that you keep making mistakes typing in links, here is something to help:
1 At the bottom of the thread there is a yellow box. Highlight the bold \ link{url\description} then use the mouse to drag it into your message (no need to cut and paste).
2 Open up another window (File, New Window) and go to the site to which you want to link.
3 Click on the url and it will be highlighted.
4 Do Edit, Copy or else hit CTRL C.
5 Go back to the Mumsnet window and your message. Highlight the word url and do Edit, Paste or else hit CTRL V.
6 Highlight the word description and overtype the description.
Bob's your uncle.
If you're not sure of yourself, click on Preview conversation to check the link.