Static instance variables or methods appear in underline
Generalization (inheritance) relationships: class = solid line, interface = dashed line
Associational (usage) relationships, i.e. one class contains instance(s) of another: solid line with diamond labeled with variable name (or thin non-triangle arrow as in ObjectAid UML plugin)
Associational (usage) relationships: indicating multiplicity with *, 1, 0..*, etc.