To set the mark out, represented by the yellow and marking the end of your cut you have to :
•Place the playhead where you want to place the yellow line.
•Click on the following icon :
.
NB : you can also set the yellow line by using the right click of your mouse (function available in "Snippet" only ) or use F4 (shortcut) (see Snippet shortcuts).
In addition, note that by right-clicking on the blue or on the yellow icons, the marks on the track will disappear.