Question about installing Ubuntu

[Pamich]

From the wiki about triple booting Ubuntu:

"When it comes time to set up the partitions, do so manually. Because we only are able to have four primary partitions setup for the MBR mirror and Apple has already taken the first spot with the EFI System Partition, we will need to only mount the / drive to /dev/sda3, nothing else, not even a swap. This will cause an error to get thrown about decreased performance or installations errors from the lack of a swap... it will be fine and will actually install faster (I had 1 gig of RAM, so I can't guarantee anything under that). I recommend formatting the partition."

I selected to do it manually. It says mount the / drive to sda3 and nothing else, so I cleared the other options so / to sda3 was the only thing and the other 3 slots were blank. When it went to confirm, it said:

"WARNING: This will destroy all data on any partitions you have removed as well as on the partitions that are going to be formatted."

Am I interpreting the instructions horribly wrong or is that what I want to do?

[jido]

The wording is bad. It will destroy data on partitions that you have deleted using the partitioning tool. Read the rest of the message, it will tell you which partitions will be affected.