There may be an occasion where you need to hold a combination in a particular place in the Start Lists, regardless of what moves are made around them. They may have multiple rides and you need to separate them or they may have a reason for needing to go first in the draw, for example.
Pinning is very simple to do.
From Step 2 of the Times locate the combination you would like to "Pin" in place
Click the 3 dots to the right
Select Pin Combination from the drop down menu:
Pinned combinations are shown with a symbol, as below:
To "Un-Pin" simply click the 3 dots again and select "Unpin Combination"