Hi Anne,
You're right, that site is a useful support site for for those forums that use BBCode, a forum using the phpBB package, for example. The reason for offering BBCode is that these forums do not allow you to post in HTML. Users, wanting to employ special formatting, have to post using the alternative BBCode. As you obviously realise, much of it is similar to HTML. The principle difference is that it uses [Square Brackets] rather than <Angle Brackets> as delimiters for tags.
Nabble doesn't use BBCode. It allows users to post directly in HTML, so pointing people to a BBCode reference may confuse some of your users. (The syntax for lists and quotes, for example, are significantly different.)
It is not surprising the BBCode site does not include codes for a new line, since, like posting in a Nabble forum with HTML turned off, all you need to on a BBCode enabled forum is to hit the carriage return (i.e. Enter) key a couple of times.
Your advice to use a couple of <br> codes, is not ideal. When posting with the HTML option enabled, text should be tagged using appropriate semantic mark up, i.e. the various tags for headings, paragraphs, lists, etc. should be used. Nothing should be left as "body text" as it would be the way you recommend.
<p>If text is marked up as a paragraph, as this sentence is, then, unless your CSS asks it to be shown differently, it would be rendered by any browser with a 1em margin above and below.</p>
For an alternative to the BBCode site, You could do worse than point people at:
http://www.htmlhelp.com/reference/html40/olist.htmlIt's now somewhat old and no longer actively maintained, but from that index page good descriptions of everything a Nabble HTML poster is likely to require (with a mass of background he won't) is just one click away.
Volunteer Helper - but recommending that users move off the platform!
Once the admin for GregHelp now deleted.