A log sent to hamlog.online by hand — an ADIF exported from OpsLog and dropped
on their site — had no way of being marked as sent afterwards. The QSL Manager
then listed every one of those contacts as backlog and offered to upload them a
second time.
Both HAMLOG keys join the bulk-editable extras, so a selection (or the whole
log) can be stamped in one pass. They are DATES rather than Y/N flags because
that is the shape the sent stamp already uses: the QSL Manager's backlog asks
whether the key is present, and a date also says when it went.
The test pins that they are reachable through the extras path and NOT offered as
columns — a mapping claiming both would write to a table that has neither.