Update exchange/exchange-ps/exchange/Remove-AuthenticationPolicy.md

Co-authored-by: David Chesnut <[email protected]>

Author: chrisda

exchange/exchange-ps/exchange/Remove-AuthenticationPolicy.md

@@ -77,7 +77,7 @@ The AllowLegacyExchangeTokens switch enables legacy Exchange tokens to be issued
 
 Legacy Exchange tokens include Exchange user identity and callback tokens.
 
-This switch applies to the entire organization. Although the Identity parameter is required, its value is ignored. You can pass any non-empty value as the Identity parameter.
+This switch applies to the entire organization. The Identity parameter is required, and its value must be set to "LegacyExchangeTokens". Specific authentication polices can't be applied.
 
 **Important**: