Update Set-Mailbox.md

Author: chrisda

exchange/exchange-ps/exchange/mailboxes/Set-Mailbox.md

@@ -101,6 +101,7 @@ Set-Mailbox [-Identity] <MailboxIdParameter>
  [-ForwardingSmtpAddress <ProxyAddress>]
  [-GMGen <$true | $false>]
  [-GrantSendOnBehalfTo <MultiValuedProperty>]
+ [-GroupMailbox <MailboxIdParameter>]
  [-HiddenFromAddressListsEnabled <$true | $false>]
  [-IgnoreDefaultScope]
  [-ImListMigrationCompleted <$true | $false>]
@@ -381,6 +382,7 @@ Set-Mailbox [-Identity] <MailboxIdParameter> [-RemoveDelayHoldApplied]
  [-ForwardingAddress <RecipientIdParameter>]
  [-ForwardingSmtpAddress <ProxyAddress>]
  [-GrantSendOnBehalfTo <MultiValuedProperty>]
+ [-GroupMailbox <MailboxIdParameter>]
  [-HiddenFromAddressListsEnabled <$true | $false>]
  [-ImListMigrationCompleted <$true | $false>]
  [-ImmutableId <String>]
@@ -2884,7 +2886,10 @@ Accept wildcard characters: False
 
 ### -GroupMailbox
 This parameter is available only in the cloud-based service.
-The GroupMailbox switch is required to modify Group Mailboxes in Exchange Online.  You can use any value that uniquely identifies the group mailbox. For example:
+
+The GroupMailbox switch is required to modify Group Mailboxes in Exchange Online. You don't need to specify a value with this switch.
+
+You can use any value that uniquely identifies the Group Mailbox. For example:
 
 - Name
 
@@ -2906,9 +2911,9 @@ The GroupMailbox switch is required to modify Group Mailboxes in Exchange Online
 
 - User ID or user principal name (UPN)
 
-```Telaws
+```yaml
 Type: MailboxIdParameter
-Parameter Sets: Identity
+Parameter Sets: Identity, RemoveDelayHoldApplied
 Aliases:
 Applicable: Exchange Server 2013, Exchange Server 2016, Exchange Server 2019
 Required: False
@@ -4303,7 +4308,7 @@ The RemoveDelayHoldApplied switch specifies whether to remove delay holds from t
 
 The removal of a hold from a mailbox is temporarily delayed to prevent the accidental purge of content that's no longer affected by the hold. This temporary delay in the removal of the hold is known as a delay hold. To see the hold history on a mailbox, replace \<MailboxIdentity\> with the name, email address, or alias of the mailbox, and run this command: Export-MailboxDiagnosticLogs -Identity \<MailboxIdentity\> -ComponentName HoldTracking.
 
-The RemoveDelayHoldApplied switch can also be used with the GroupMailbox switch in order to remove delay holds from group mailboxes.
+You can use this switch with the GroupMailbox switch to remove delay holds from group mailboxes.
 
 ```yaml
 Type: SwitchParameter