Key
wu = warm up
set = main set
wd = warm down (or cool down)
fs = freestyle
fl = butterfly
1a fl = 1 arm fly
bk = backstroke
2a bk = double arm back
br = breaststroke
bk/br = bk or br or a mix of both
IM = Individual Medley (= fl + bk + br + fs)
rev IM = reverse IM (= fs + br + bk + fl)
drop a stroke IM = start from a full IM and on each following repeat omit one of the strokes
  (e.g. drop a stroke IM starting from a 200 assuming your favourite stroke is back and your
  second favourite free, and fly your least favourite, would be: 200IM; 150 = 50bk+50br+50fs; 
  100 = 50bk+50fs; 50bk)
add a stroke IM = opposite of drop a stroke
  (ensure that you swim the strokes in the same order as you would in "drop a stroke IM")
ch = choice (any of the 4 strokes)
k = kick (legs only)
p = pull (arms only)
sw = swim (full stroke)
dr = drill (emphasizing a particular aspect of your stroke)
r = right arm only (swim with the right arm only; left arm above your head in fs, at your 
  side in bk)
l = left arm only (swim with the left arm only; right arm above your head in fs, at your 
  side in bk)
cu = catch up (arms meet above your head before starting the next stroke)
long = long strokes - stretch!
dps = focus on distance per stroke (similar to "long") 
ez = easy (slow pace)
golf = add up # strokes and # seconds swimming
mod = moderate pace
hard = fast pace
even pace = same speed all the time
build = start moderate and build up to hard
fade = start hard and slow down to moderate
desc 1->3 = descending from #1 to #3 (#1 mod, #2 a bit faster, #3 hard)
alt = alternate
neg sp = negative split (2nd half faster than first)
br 3/5 by 50 = breathing pattern alternating every 3 strokes for 50m with every 5 strokes 
  for another 50m
w :30 rest = with 30 seconds rest between repeats
+ 10 = with 10 seconds rest between repeats (alternative notation to the above)
 
2 x (200, 100, 50) :  each 200 (or 100 or 50) = 1 repeat
                      each ( 200 + 100 + 50 ) = 1 set
  Thus this reads: 2 sets of 3 repeats, one each of 200m, 100m and 50m
 
Note that we never use the word "lap" as to some people it means 2 lengths and to others 
it means 1, so we just use "length", where 1 length = from one end of the pool to the other.