01d74549_ikipedia_Vandalism___Wikipedia__Type
[Description] Illegitimately deleting or editing other users' comments. However, it is acceptable to blank comments constituting vandalism, internal spam, or harassment or a personal attack. It is also acceptable to identify an unsigned comment. Users are also permitted to remove comments from their own user talk pages. A policy of prohibiting users from removing warnings from their own talk pages was considered and rejected on the grounds that it would create more issues than it would solve. [Type] 
Talk page vandalism
Wikipedia:Vandalism - Wikipedia
Type