1 | initial version |
I'm not entirely certain where the 3rd party site you refer to gets its info, likely just a copy of the actual Wireshark documentation, but it's certainly out of date. The perils of not using the actual source of the info.
Either use the help installed with your version of Wireshark which is likely to be mostly in-line with the features in your version, or use the development docs here that may be slightly different from your version.
There is no compare dialog in current versions, it was removed when the UI toolkit changed to Qt, so probably still in 2.6.x if you enable the GTK+ UI on install.