The gist of OCV is this:

If you have any two weeks of vacation in a four week pay period, you can opt into Optional Crewmember Vacation which gives you two choices:

1. Sell back your vacation @ 5hr/day, meaning you'd get 70hr of pay on top of line credit for that pay period, OR

2. Take the entire four week pay period off.

OCV allows people to bid whatever they want (or whatever they can hold) instead of whatever maximizes their vacation conflict...and overwhelmingly, people are electing to take the time off. Pilots can pick up OT or accept JAs while out on OCV so long as those trips don't fall on their awarded VAC weeks.

Beginning in 2018, there will be a one-week vacation slide option to OCV which will allow people with a single week of vacation to slide it beginning on the front of a trip or ending on the back of a trip, potentially increasing conflict and allowing any VAC days falling on a day off to pay 5hr/day instead of the current 3hr/day.