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+A subflow is a set of connected nodes that can be easily referenced and reused within a larger flow.
+
+A subflow is represented as a single node in the workspace which can be opened up in a tab to see the underlying flow.
+
+A subflow can be used in one of two modes: (this is tbd. Might just stick with singleton for v1)
+
+1. Singleton : only one copy of the flow exists.
+2. Instance : each reference to the subflow is its own copy.
+
+### Creating a subflow
+
+1. User selects some existing nodes.
+2. Selects 'convert to subflow' option.
+4. Dialog opens to name the subflow.
+3. Nodes are removed from workspace and replaced by a subflow node.
+4. Subflow node added to palette
+
+**Questions:**
+
+* how to automatically identify the input/output ports to map to
+* what restrictions should be applied?
+    * a single, continuous flow of nodes - aside from comment nodes
+    * only one 'left most' node
+
+
+### Editing a subflow
+
+1. Double click subflow node.
+2. Opens in closeable tab containing the flow. 
+
+**Questions:**
+
+* how to rename the flow? Via subflow sidebar tab?
+* how to pick singleton/instance mode? 
+
+### Delete subflow
+
+1. Open a subflow sidebar tab that lists all subflows with usage count (cf config node tab - perhaps combine them...?)
+2. ...
+
+
+## Definition
+
+...
+
+
+