Based on the SS above, let's say
1 lot SELL GJ 134.28
1 lot BUY GU 1.5590
1 lot BUY UJ 86.17
actually we have exposure 0.559 (actually GU price 1.5590-1) lot for UJ, for the example above, we SBB means that we selling UJ (0.559 lot).
SBB for GJ GU UJ or EJ EU UJ means we are selling UJ. When UJ drop, we only earn. Why don't we straight aways trade UJ to save the spreads.
If we wanna sell GJ 10lot, buy GU 10lot, buy UJ 10lot (means SBB), we can sell UJ only with (GU price x 10 lot - 10lot), 1.5590 x 10-10=5.59lot, mean we only sell UJ 5.59lot in order to save spreads.
For those who test this strategy before, you can check back your statement with this calculation, you will find out that u will earn more by only trading UJ instead of 3 pairs together.
