The Exchange Management Shell follows several command conventions that help you understand what information is required or optional when you run a command and how you must present the parameters and their values. See the Parameter Sets section later in this topic for examples of how parameter sets are presented in the Exchange Management Shell Help and Exchange 2007 Help file.

Table 1 lists these command conventions.

Table 1   Exchange Management Shell command conventions

These command conventions help you understand how a command should be constructed. You don't type these conventions when you enter the command on the command line.

In the Exchange Help documentation, all cmdlets display their associated parameters in parameter sets. Parameter sets are groupings of parameters that can be used with each other. Parameters that exist in one parameter set, but not in another parameter set, are mutually exclusive. They can't be used together.

Although all cmdlets have parameter sets, many only have one set of parameters. This means that all the parameters on that cmdlet can be used with each other. Other cmdlets may have several parameter sets. The following example displays the parameter sets that are available on the New-SystemMessage cmdlet:

New-SystemMessage -DsnCode <EnhancedStatusCode> -Internal <$true | $false>
-Language <CultureInfo> -Text <String> [-DomainController <String>] [-Templ
ateInstance <MshObject>]

New-SystemMessage -Language <CultureInfo> -QuotaMessageType <WarningMailbox
UnlimitedSize | WarningPublicFolderUnlimitedSize | WarningMailbox | Warning
PublicFolder | ProhibitSendMailbox | ProhibitPostPublicFolder | ProhibitSen
dReceiveMailBox> -Text <String> [-DomainController <String>] [-TemplateInst
ance <MshObject>]

The New-SystemMessage cmdlet has two parameter sets. The first parameter set contains the DsnCode parameter and Internal parameter, and the second parameter set contains the QuotaMessageType parameter. This means that the DsnCode parameter and Internal parameter can be used with each other. But they can't be used with the QuotaMessageType parameter. The remaining parameters, Language, Text, DomainController, and TemplateInstance, are listed in both parameter sets. This means that they can be used with the DsnCode parameter and Internal parameter and with the QuotaMessageType parameter.

Parameter sets can indicate that a single cmdlet may have multiple uses. For example, you can use the New-SystemMessage cmdlet to configure customized delivery status notification (DSN) messages or configure customized mailbox quota limit messages. However, cmdlets typically have multiple parameter sets because one parameter may perform a function that is incompatible with another parameter. For example, the following example displays the parameter sets for the New-AddressList cmdlet:

New-AddressList -Name <String> [-Company <MultiValuedProperty>] [-Container
 <AddressListIdParameter>] [-Department <MultiValuedProperty>] [-DisplayNam
e <String>] [-DomainController <String>] [-IncludedRecipients <Nullable>] [
-StateOrProvince <MultiValuedProperty>] [-TemplateInstance <MshObject>]

New-AddressList -Name <String> [-Container <AddressListIdParameter>] [-Disp
layName <String>] [-DomainController <String>] [-RecipientFilter <String>]
[-TemplateInstance <MshObject>] 

In the New-AddressList cmdlet, the first parameter set lists parameters that let you create a new address list based on values supplied to the Company, Department, IncludedRecipients, and StateOrProvice parameters. However, you can also create a new address list by using a custom filter that is specified with the RecipientFilter parameter. When you create a new address list, a custom filter that was specified by using the RecipientFilter parameter overrides anything that was configured by using the parameters that exist in the first parameter set. Therefore, the RecipientFilter parameter is put in its own parameter set. Exchange 2007 doesn't let you specify both parameters on the same command line. As with the New-SystemMessage cmdlet, the remaining parameters that exist in both parameters sets in the New-AddressList cmdlet can be used in any combination.

Double quotation marks ( " ) are most commonly used to enclose a value that has spaces when you pass that value to a parameter. For example, if you want to pass Contoso Receive Connector to the Name parameter of the Set-ReceiveConnector cmdlet, you must enclose Contoso Receive Connector in quotation marks as in the following example:

Set-ReceiveConnector -Name "Contoso Receive Connector"

If you don't enclose the string in quotation marks, the Exchange Management Shell tries to interpret each word in the string as a new argument on the command line and displays an error.

In the Exchange Management Shell, double quotation marks and single quotation marks ( ' ) have different meanings. When you enclose a string in double quotation marks, the Exchange Management Shell replaces any variables with a matching value. For example, assume the value ServerName is assigned to the variable $Server. Then, assume the following command is entered on the command line:

"$Server Example"

The following output is displayed:

ServerName Example

The variable $Server is replaced by the value ServerName in the output.

When you enclose a string in single quotation marks, the Exchange Management Shell doesn't try to replace variables with a matching value. Assume the variable $Server is still assigned the value ServerName. Then assume the following command is entered on the command line:

'$Server-Example'

The following output is displayed:

$Server-Example

The variable $Server has not been replaced with a value because the Exchange Management Shell doesn't interpret variables that are included in text that is enclosed in single quotation marks.

For more information about variables, see User-Defined Variables and Shell Variables.

You may also want to display some characters, such as the dollar sign ( $ ), double or single quotation marks, or back quotation mark ( ` ). These characters have special meanings when you use them in the Exchange Management Shell. To instruct the Exchange Management Shell not to interpret these characters and to display them when they are included in a string that is enclosed with double quotation marks, you must use the back quotation mark escape character ( ` ). For example, type the following text on the command line:

"The price is `$23."

The following output is displayed:

The price is $23.

Because we used the back quotation escape character with the dollar sign ( $ ), the Exchange Management Shell doesn't interpret the $ as the beginning of a variable.

If you enclose a string in single quotation marks, you don't have to escape any character unless you want to display a single quotation mark in a string. If you want to display a single quotation mark in a string that is enclosed in single quotation marks, you must use two single quotation marks ( '' ). For example, type the following on the command line:

'Don''t confuse two single quotation marks with a double quotation mark!'

The following output is displayed:

Don't confuse two single quotation marks with a double quotation mark!

Use the operators in Table 2 when you type commands in the Exchange Management Shell. Some of the operators may match some of the previously mentioned command conventions. But they don't have the same meaning when they are typed on the command line. Table 2 shows the valid operators that you can use in a command.

Table 2   Exchange Management Shell command operators