I have noticed several instances where another contributor has modified entries I have made over the preceding months and years, without advising me. Having initiated a discussion with the reviser and received an explanation that I felt was inadequate, I provided further explanations and requested the reviser to reverse the changes that they had made, and that I would agree to taking the matters over which we disagree to an open forum, if there was still a disagreement.
At this time the revisions I disagree with have not been reverted, and I have heard nothing further from the reviser.
I can make the reversions myself, which will involve significant work, or I can choose to abandon OpenStreetMap altogether, on the basis that there is no effective protocol to protect my contributions from changes without notice or discussion.
I welcome comments from other contributors on the protocol for dealing such conflicts of opinion.