Only for input pins, mark this pin as required.If set on an output pin, behave as Normal.
Advanced
Advanced pin will be hidden by default in the UIand will be shown only if the user extends the node(in the UI) to see advanced pins.Pins can't be required and advanced at the same time.
UMETA
Pins generated by overridable parameters (normal nodes) or user parameters (subgraph nodes) - note that these are considered advanced pins.