Syntax: TAB defines quote

To quote a paragraph, just prefix it by a TAB character. All the lines of the paragraph must begin with a TAB.

Any non-tabbed line closes the quote block.

Nesting: Creating deeper quotes

The number of leading TABs identifies the quote block depth. This is quote level 1.
With two TABs, we are on the quote level 2.
The more TABs, more deep is the quote level.
There isn't a limit.

Nesting: Reverse nesting works

This quote starts at level 4.
Then its depth is decreased.
Counting down, one by one.
Until the level 1.

Nesting: Random count

Unlike lists, any quote block is independent, not part of a tree.
The TAB count don't need to be incremental by one.
The nesting don't need to follow any rule.
Quotes can be opened and closed in any way.
You choose.

Nesting: When not supported

Some targets (as sgml) don't support the nesting of quotes. There is only one quote level.
In this case, no matter how much TABs are used to define the quote block, it always will be level 1.

Syntax: Spaces after TAB

Spaces AFTER the TAB character are allowed. But be careful, it can be confusing.

Invalid: Spaces before TAB

Spaces BEFORE the TAB character invalidate the mark. It's not quote.

Invalid: Paragraphs inside

Paragraph breaks inside a quote aren't possible.

This sample are two separated quoted paragraphs, not a quote block with two paragraphs inside.

Closing: EOF closes the open block

The end of the file (EOF) closes the currently open quote block.