I didn't see anything on the PMBOK guide. But Forcing comes with the PM Authority derive from an organization or what ever you call. SO if you force some one he/she will do the work but Avoiding means to leave the issue or escape from the responsibilities.

I would choose Withdrawl as the least preferred type of conflict resolution... Because as a Project Manager you need to get the job done.

Thanks.

The PMP Guru

http://thepmpguru.wordpress.com/