Loops

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