Symbol Rules

Symbols represent values (constants or variables) to make source code easier to understand and maintain. To use them, one must create them according to the following rules.

Symbols:

Are case-insensitive. That means that all of the following symbols are equivalent.
```
foobar
FooBar
FOOBAR
```
Must start with and contain only letters, numbers, and underscores (a-z, A-Z, 0-9, _); no spaces allowed.
Must be 30 characters or less.
Must be unique within the current Spin object; i.e., not a Reserved Word (like BYTE, PAR, WAITCNT, etc.) or a previously defined user symbol.