| 摘要 |
A data synchronisation protocol is initiated by a client device 201 (eg a mobile phone as in fig. 5) based on data it stores (403, fig. 4) about the filtering capability of a server device 202. This minimises the amount of data to be transmitted without risking errors caused by clients requesting filters which the server does not support. In the synchronisation data, the filtered data is substituted by an indicator of that filtered data so that subsequent updates do not simply undo any Soft Deletion operations and so that the receiver of the filtered data can be informed of what to do with any copies of the filtered data it is currently storing. The indicator can be a Field Filter Marker (106, fig. 1), a Field Soft Delete Marker (207 or 307, fig. 3) or a Restore Marker (211). |
