My personal interpretation would be a combination is numbered A and B where as a related distance would be too separate jumps eg 7 and 8 but on a set number of strides, eg only 4 strides between. A combination would be a double or treble eg 7a and 7b or 7a 7b 7c with only one or two set strides between elements
a combination is either a double or a triple, same numbered element with 1 to 2 strides in between each element. A related line is 3+ strides between two seperately numbered jumps
