The Identification operator, localization and labelization. The "Find panel" (a) first allows selection of a highlighting operation: symbol or text annotation but also foreground or background colors, shrinking sub-tree and so on. Then the user either selects a leaf label from a list or enters a string pattern. In this example the pattern "STE*" highlights leaf labels starting with "STE" (red symbol facing leaf labels). Labelization consists in browsing a tree, selecting sub-trees and posting annotations associated to its leaves (b). Localization operates in the opposite direction; it consists in querying annotations associated to leaves and highlighting tree's elements. The Identification panel (c) enables localization and multi-localization (localization on tree collections), it includes a SQL like interpreter. For instance, a "protein tree" is automatically colored according to 'Cellular role' annotations from Yeast Proteome Database .