Just discovered this so I thought I'd pass the tip along. If you want to post text with single spacing, first type it into a Notepad document and then copy/paste it here.
Forum Single Spacing

Steven-W15
March 1, 2015

Dan-H24
March 1, 2015
Hmmm...that really didn't work for me. I copied and pasted text from Open Office Writer and from Text Edit, the Apple equivalent of notepad, I think, and it all looks the same to me.

Robert-C7
March 1, 2015
What works for me is to type Shift + Enter.
Here, I just did it.
Here I just hit Enter.
Also, I just learned that is you put anything in angle brackets, it apparently thinks it is an HTML tag and effectively removes it. Hmmm.

Steven-W15
March 2, 2015
Shift+Enter doesn't work for me (PC). Copy/paste from Notepad does. Must be platform specific.
One line
Two lines
jason☺
March 2, 2015
The shift-enter trick seems to work on Chrome (mac, pc).
Here RL is using CKeditor 4.4.7 (you can inspect the javascript via most browsers to see what's going on). Here are the keyboard shortcuts:
Link: http://docs.ckeditor.com/#!/guide/dev_shortcuts
It is interesting that the demo presented by the company is quite different from what we see here at RL.
Link: http://ckeditor.com/demo
jason☺
March 2, 2015
The system can be configured to create br or p or div breaks.
http://ckeditor.com/demo#enter
jason☺
March 2, 2015
If ckeditor turns out to be too hard to implement, they could consider using another option
Link: http://www.tinymce.com/
or one of these:
Link: http://socialcompare.com/en/comparison/javascript-online-rich-text-editors

Steven-W15
March 2, 2015
Thanks, Jason. shift-enter does indeed work for me.