If you do not set up a sync tag inside the SyncML fields for incoming and outgoing then 'ALL' your contacts will be copied over to your iPhone or Android mobile as contacts. 

Unless you want potentially thousands of contacts from icomplete added as contacts on your iPhone/Android mobile please make sure that you set up a new tag for sync such as 'sync-yourname' etc and add this tag into the Settings - Your Settings SyncML fields as shown below:

Make sure you have entered your tag into both the Incoming and Outgoing fields and click on 'Update Settings' as shown above.