Xpath
/control/member-list[@sync-mode]
Possible values
add
replace
replace_keep_bounces
sync
sync_update_attributes
sync_update_attributes_no_add
delete
add
add_update
update
add_mode
add_member_mode
add_update_mode
add_user_update_mode
update_mode
replace_mode
delete_mode
Example
<member-list sync-mode="replace_keep_bounces">