This page explains how a client groupware user can control what items will or will not be synchronized during synchronization.
When synchronizing with CRM the first time all items will be displayed in the conflict resolution screen.
To avoid an item being synchronised you can select the skip option.
When choosing this the selected item will not be synchronised.
After this upon the next synchronization the item will again be suggested for synchronization.
If the user would like to prevent this from synchronization they can add the item to the excluded list.
Once in the excluded list the item will not be considered for synchronization.
If at a later date you would like to revert this you can remove the item from the exclude list on synchronization thereafter the item will again be considered.
Groupware Options -> Advanced tab -> Check "Temporarily Include Exception List Entries"