From Xojo Documentation
Makes all of the public declarations in a module (or namespace) available for inside the scope of the code as if it were defined there.
The only legal identifier for a Using statement is a module (namespace) name. The first identifier will be resolved recursively, from inner to outer scope as usual. If you would rather skip the recursive search, you may use the Global prefix.
When Using is used in code, it obeys code block scoping rules.
You can also use Using with classes and modules (Insert ↠ Using Clause). When used in this manner, the Using applies to the entire class or module and all code contained within it.
Access the Dictionary without using its full namespace:
Avoid the Xojo namespace:
Code block scoping: