This enum defines what subset of the PowerShell language is permitted when calling into this execution environment.
public enum PSLanguageMode
Exposes a subset of the PowerShell language that limits itself to core PowerShell types, does not support method invocation (except on those types), and does not support property setters (except on those types).
All PowerShell langugage elements are available
Commands containing script text to evaluate are not allowed. You can only call commands using the Runspace APIs when in this mode.
A subset of language elements are available to external requests