You may be working in a sketch, make changes , and then realize you don't need to make those changes. How can you finish the sketch without saving the changes you just made?
Solution
After making the sketch changes you have 2 options to cancel the changes:
1) Select the Undo option to see the list of undo points and select "Open sketch"
2) Select the Task tab and select "Exit Sketch" from the list.
Notes and References
Hardware/Software Configuration
Platform: INTL64
OS: windows
OS Version: 1064
Product: NX
Application: DESIGN
Version: V1899
Function: SKETCHER
Ref: 001-9714076