I'm not a native speaker, so i apparently poorly frased my question.
Here's another go:
If users work in an online editor they hit the a return-key to start a next line on a next rule. If they want to leave an empty rule they hit the return-key again. The editor now puts another <br> in the code.
But: if a letter-spacing is in the style of the text there's no empty rule, only if the user hits the key for the third time there it is.
I cannot understand this and don't know a way around this problem.
Hope this is understandable now.
letter-spacing versus <br> refrased
It is a bit hard to understand so if possible post a link to an example.
Sounds like the problem is with the editor software used.
If the editor is just a text box that you then format you might be able to use "pre" tags to format as it looks to the user that entered it.
Hope that helps.