If you are wanting to setup Call Park buttons on a Cisco phone, use the following Example for the Strings:
For Parking a Call:
fnc=sd;ext=700@202.52.129.60;nme=Park Call
For Retrieving Call 1:
fnc=blf+sd;ext=P701@202.52.129.60;sub=P701@202.52.129.60;nme=701

For help setting up Call Parking from within your MaxoTel account, please follow our Call Parking Guide