FAQ: Where can we place blocks ?

Mast blocks are put generally below mast caps.
Halyard blocks (D) take place in front of the upper mast.
Put mast cap blocks before assembling masts to mast caps.
Put also stay blocks before placing masts on the model.
Go through plans carefully not to forget a mast block. Once a mast is stepped, it is always difficult to place a block down there.