Apart from the standard monitor types you can use on a monitor item, a number of embedded monitor types also exist. An embedded monitor type is one that is embedded in the thing it is supposed to monitor.
At the time of this writing, two types of embedded monitor are supported: Ingoing and outgoing transport types. What this means is that if you have an ingoing or outgoing transport location using a transport type that supports embedded monitoring, you can set up a monitor item directly on the transport location.
The monitor item will then use the configuration of the transport location to connect to whatever it is the location connects to, and perform whatever checks that monitor type does.
You will be able to see the monitor item in the normal monitor item view, and you can also open it there to see its configuration. In that view, however, you can only see the generic configuration fields common to all monitor items. To see the full configuration and/or edit it, you have to go to the detail view of the transport location the monitor item belongs to. This is facilitated by a button in the monitor item detail view which will let you navigate directly to the detail view of the matching transport location.