How can I have two boxes with the same name?

Question

Two questions:

(1) What type of diagram is this?

@startuml

(*) --> x

x --> y

y --> z

@enduml

(2) Imagine I want to alias 'z' so that it is still a seperate box, but it appears as 'y' (so on the diagram x flows to y, and y flows to another y). I've tried using the 'as' keyword but it doesn't seem to work. Maybe there is something I'm missing.

Answer 1

(1) looks like an activity diagram. However, PlantUML try to guess people intention and sometimes get wrong, especially on small text.

About (2), you may use the new syntax for activity:

@startuml
start
:x;
:y;
:y;
@enduml

But I'm not sure that this is your need.