If you get the question from your FTP client on a folder, you choose to merge with existing folders. When/if you then get the question on a file, you choose to overwrite existing files. That's what was meant by merge and overwrite. Because you want to merge folders (so no existing files that is not within your patch folder (but is within the selected folder on the server) gets deleted). You usually only get the merge option if it's about a folder. As merging an already existing file with a new file with the same name would not be an sensible option for an FTP client.
Some FTP-clients will provide the option of "Merge and overwrite" right away, which means it will merge folders and overwrite files.
PixlBendr reacted to TSP in IP.Board 3.3.x, 3.4.x and IP.Nexus 1.5.9 Security Update
