If node is instance of a concept which implements ISuppressErrors interface, then all errors in this node and it's children won't be shown. It is also possible to define define child roles, where errors should be suppressed, by overriding interface boolean method suppress(node<> child).
Also if node has attribute of concept implementing ISuppressErrors, errors in such node will be suppressed too.
There is default implementation of ISuppressErrors node attribute. It can be applied only to nodes that are instances of ICanSuppressErrors.