Optional block feature executes or skips lines of program that have character '/' at the beginning of the program line.
This feature comes useful when you need to test proof your program or if you have two versions of the same workpiece with minor changes etc…
In such case you can use Optional Block Enabled feature which allows you to skip or execute marked lines of G-code of your program.
When Optional Block Enabled is enabled, then marked lines will be skipped.