A variable with level scope cannot be referenced outside of its current hierarchical level. Variables with hierarchical level scope are referred to as local variables. Although level scoping is the most restrictive type of scope, it has several key advantages. By limiting the region over which variables can be referenced, you can construct sections of a diagram without worrying about whether your variable names conflict with other names used in other parts of the diagram. In addition, users reading your diagram will know immediately that the variables’ use is limited to a small region.
Variables with level scoping are prefaced with the colon (:) character.