It locks all of the fields unless you unlock them. This also stops you from being able to link to the description field for each item under the weldment properties..
SW2018 SP0.1. this was not the case in SW2017 or earlier. If you link a note to the description in your drawing it uses the description of the part and not the description of the item in the cut list. Also if you want to change the value of any of these you have to uncheck the "Linked" column to change them. This is just more steps.
2017 there is not a column for the "link" what does this feature do anyway? it only makes things harder. I almost always rename items from "PLATE" or "SHEET" to whatever they are called in that weldment.
VAR has not been entirely helpful. They have looked into it but it takes at least week between answers which have not worked.