Reverse Dependencies supported?
 

Clearly, it is possible to have tasks in a plan be prerequisties of tasks which precede them in the layout.

Currently the only way I can create those in Plan is to reverse the order of the tasks, create the dependencies and move them back. In MS Project you just input into the dependencies list the numbers of the dependecies and prerequisites directly.

Am I missing something? Is there a way to do this or a rationale for not doing it?

You want to select both tasks, then click-and-hold on the 'connection' button; a menu with additional connection types will appear.

The 'Connecting tasks with dependencies' page in the help menu material explains what the different connection types mean.

brian, the connections that are made are always S->S F->S S->F F->F and I'm asking about the other way, S<-S, F<-S, S<-F, F<-F
Thanks.

To create a dependency the other way, you can hover your cursor over a task bar in the gantt chart until you see two arrowheads show up. Click and drag the arrowhead from one end of the task to the other end of the task above it.

For example, to set up a S->S dependency from task 2 to task 1, drag an arrowhead from the beginning of task 2 to the beginning of task 1.

You can also show the dependency column in the task outline and then type directly in that column.