None.

None.

Inside a block-quote or a paragraph, a single newline is an implicit line break.

Here's a normal paragraph
with implicit line breaks
in several places at once.

> One level of block quoting. 
> The quick brown fox
> jumps over the lazy dog.

Here's a normal paragraph
with implicit line breaks
in several places at once.

Here's a normal paragraph with implicit line breaks in several places at once.> One level of block quoting. The quick brown fox jumps over the lazy dog.Here's a normal paragraph with implicit line breaks in several places at once.