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* means zero or more of these preceding events. Since it's zero or more, it will collect a direct lighting event and the ones that follow it (meaning indirect) til they reach a light source. It's the simplest way to capture light for the whole path. The following collects only diffuse reflection and all the events that match diffuse reflection until it strikes reaches a light.

lpe:C<RD>*[<L.>O]

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The curly brackets can also take a range of values to render a set of bounces. Maybe you're only interested in collecting the effects of the 4th through 8th bounce? Or maybe you know where to begin or end but want the renderer to decide where that is.

Think of it like this, A is where we will begin and B is where we will end. It's written like this: {A,B}

Collect just the 4th through 8th bounce
lpe:C<[RT][DS]>{4,8}[<L.>O]
 
Collect all the bounces until you reach the 5th bounce
lpe:C<[RT][DS]>{,5}[<L.>O]
 
Start at the 3rd bounce and go until the path is finished
lpe:C<[RT][DS]>{3,}[<L.>O]

The following examples show these actions. Note that when we leave the beginning or ending blank, the renderer makes that decision on where to begin or end the collection.

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