Loops
In the following overview you can find a set of loops that can be done to adjust the trim of a paraglider.
Open
Standard setting on your line with no loop; some checkcenters also call this a single loop
Single Loop
Some checkcenters also call this a double loop - means that the line is looped once compared to the open state
Girth Hitch
Also known as Cow Hitch, Larks Hitch or Anchor Knot; for details see also Wikipedia
Double Loop
Line looped twice around the maillon or soft link.
Girth Hitch Plus
On side of the girth hitch is additionally looped around the maillon or soft link.
Pile Hitch
The length change for the Pile hitch is very similar to the Girth Hitch Plus. It is for most wings easier to fit it over the maillon or soft link though. For details on this loop, see also wikipedia.
Girth Hitch Plus Plus
This knot is done similar like the Girth Hitch plus, only that both sides are looped another time around the maillon or soft link.
Pile Hitch Plus
The length change for the Double Pile Hitch is very similar to the Girth Hitch Plus Plus. It is easier to fit on the maillons or soft links though.
Double Pile Hitch
To see how it's done, also compared to the Pile Hitch see https://knots.neocities.org/pilehitch