Reference to diagram

[MV]

Hi guys,

we have many activity diagrams and most of them are using a common validation steps.

I have made a separate diagram to represent these validation steps. Now I want to refer/call this little validation diagram from all those main activity diagrams.

I cant use UML patterns because dragging and dropping a UML pattern to main activity diagram will create a separate instance of this validation flow. I want to refer to this validation diagram not copying it so that if i change this validation diagram in future then all other diagrams will automatically take effect of change.

TIA/Cheers