Confusing documentation for '-l' option

The documentation says:

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The Connect IQ type checker is disabled by default and is enabled with the -l compiler option. There are four levels of type checking:

1. Silent - No type checking; keep everything dynamically typed
2. Gradual - Type check any statement where typing can be inferred, otherwise stay silent
3. Informative - Type check only what has been typed, warn about ambiguity
4. Strict - Do not allow compiler ambiguity

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But the corresponding -l options are 0, 1, 2, 3.