I am developing a workflow designer by DSL tools (Domain Specific Language) in Visual Studio,
I want to add a multi line string property as a domain property on one of my domain classes.
When I add it as string, it's only 1 line of string.
This is what I am looking for, something like Notes in DSL designer.

I found the solution, in case somebody else is looking for it too.
So we need to add
UITypeEditor, by adding this asCustomAttributeon domain propertyAlso
System.design.dllshould be added to solution tooMore info at https://msdn.microsoft.com/en-us/library/cc512860.aspx?f=255&MSPPError=-2147217396