Horizontal ruler:\\
{{{----}}}
gives you:
----


Paragraphs are delimitted by a blank line.
{{{This is Paragraph 1

This is Paragraph 2
}}}
gives you:

This is Paragraph 1

This is Paragraph 2

----

Forced Line Break: 
{{{This is first line,\\this is second line!}}}

gives you:

This is first line,\\this is second line!

----