10. The Company may proffer to liquidate a vacation period(s) in a category following notification to the MEC Scheduling Committee Chairman. This proffer may be made no earlier than sixty days prior to the affected bid period.

This is a situation where the company can make a unilateral offer. How is this different? Just because it's a company proffer? When else would a sell back happen?

We Once had a pilot option to presell vacation weeks. You simple sold what you wanted and were paid out in cash. The difference since you asked is several hundred jobs. The company has always had the option to cancel vacation weeks and buy them from the pilot. It's been used very infrequently to the point of almost never. I remember twice in 30 years.
The ability to sell vacation was used extensively by pilots.

I understand how it used to be. 10. gives them that right when its beneficial to the company. This is an out that could be applied to avoid cancelation, not part of the cancelation itself. We have the ability (under certain company controlled circumstances) to sell back vacation now. That was my point. Its not some forbidden thing that some believe.