What does this mean and how do I undo it for a cable?
What does this mean and how do I undo it for a cable?
I clarified how to uncheck (unreserve) those cable segments, see my main post I added a screenshot and further explanation, hope that helps!
Thanks for clarifying! Are you using a Line Diagram for cabling in any way? That's where I see this used...Typically this "reservation" is initiated from the Line diagram, either by right clicking (shown here) or from the detailed cabling dialogue (double click on a cable) to establish that down the road, a cable's conductors can only be associated from conductors running between identical components in schematic. So right click, and choose which set of conductors are designated from component a to component B. You can select an entire cable to reserve between 2 components, or break out conductor by conductor if they run between more than just 2 devices. To unreserve conductors, right click on a line diagram segment, choose the command, and then "uncheck" the cable as a whole or the conductors you want to free up if it was accidentally chosen. 
Can you show a screenshot? Not familiar with that wording...