After a copper pour, it is quite common for there to be areas of copper which are isolated from the main pour. Clearly this increases rather than reducing crosstalk, so a means of identifying and removing them is needed.
The Pour Copper command has the ability to remove these isolated 'islands' as it goes along, but it is possible that later changes to the routing might leave previously connected copper pieces as isolated.
For the purpose of this FAQ, it is assumed that the copper pour is part of net 'Gnd', and that the islands will become part of net 'Temp'.
First, highlight the main part of the completed copper pour, then right click and select [Net], [Change Net]. Set the new net name to "Temp" net class 'Power'. Immediately return to [Net], [Change Net], and rename back to "Gnd", class 'Power' as before, but this time tick the box marked 'Change Name Of Subnet Only'. Now select [View], [Highlight Net], and type 'Temp' in the box. All the isolated islands will highlight ready for connection or deletion.