A pen-based user interface (PBUI) that facilitates input of a delimiter to a scope in a substantially uninterrupted stroke for generating a selection-action gesture phrase. Four delimiter techniques are provided, which include a Multi-stroke delimiter, a button delimiter, timeout delimiter and pigtail delimiter. The Pigtail delimiter uses a small loop to delimit the gesture. The delimiter techniques support integrated scope selection, command activation, and direct manipulation all in a single fluid pen gesture. The delimiter techniques can also be employed to terminate a complex scope consisting of a sequence of multiple pen strokes.