Chimney Vent Connections?

I’m having a little trouble with some of the langue in the text in regards to venting a chimney. Can someone please correct my assumptions?

Passing Through

A chimney connector pipe or vent connector pipe should not pass through any floor or ceiling. It should not pass through a wall either, unless it’s listed and labeled for a wall pass-through.

As I understand the above, no vent connector pipe can pass through a floor or ceiling. A vent connector can pass through a wall only if the vent is listed as a wall-passthrough. Only a chimney vent (and not the connector pipes) can pass through floors and ceilings.

A single-wall metal pipe used as a vent connector passing through a wall, ceiling or floor must be guarded by a ventilated, non-combustible metal thimble, and must maintain a minimum clearance of 6 inches between the thimble and any combustibles.

So… a vent connector pipe can pass through a wall, ceiling or floor if it’s actually a single wall metal pipe and uses a thimble?

A non-combustible thimble must be used where a single-wall metal pipe passes through a roof constructed of combustible material. It would be uncommon to find a single-wall metal pipe passing through a ceiling, wall, floor, or roof. For unlisted single-wall chimneys and vent connectors, a single-wall metal pipe used as a vent connector must maintain a minimum clearance of 18 inches between the metal pipe and any combustibles.

I’m confused. What is the correct way to vent a chimney???