The -myaccountlists parameter is used with the $IF command to determine whether any mailing lists are available to the logged in user. This presents the same list of mailing lists that the user would see from the /MyAccount.aspx?mode=subscriptions page within iService as shown below.
Example:
$if -myaccountlists$
Yes, there are lists available to you.
$else$
No, there are no lists for you.
$endif$
For an example of using -myaccountlists to generate a table of available lists, see the My Account Subscription example.