My view is that 'sympathy' cards are to give the bereaved some comfort, to let them know that their loss is understood and shared, to an extent. To ignore someone's loss at a time of bereavement is an unkindness in itself. The actual words used are dependent upon one's closeness to the bereaved and/or the loved one. If in doubt, just a short message before your signature. Choice of an appropriately worded card can be important too, some are quite lengthy. Whatever you put, trt, I am sure the sentiment will be appreciated. Over the years I have received quite a few, but the ones I appreciated the most came from unexpected quarters.