Some aggregators, like Planet, sort by mtime rather than ctime. This
means that posts with modified content come to the top (which seems odd
to me, but is presumably what the aggregator's author or operator
wants),

> Hah! That's so charitable I hope you can deduct it from your taxes. ;-)
> --[[Joey]] 

but it also means that posts with insignificant edits (like
adding tags) come to the top too. Atom defines `<updated>` to be the date
of the last *significant* change, so it's fine that ikiwiki defaults to
using the mtime, but it would be good to have a way for the author to
say "that edit was insignificant, don't use that mtime".

> Yes, this is a real limitiation of ikiwiki's atom support. --[[Joey]] 

See smcv's 'updated' branch for a basic implementation, which only affects
the Atom `<updated>` field or the RSS equivalent.

Other places the updated metadata item could be used (opinions on whether
each should use it or not, please):

* sorting by mtime in the inline directive
* displaying "last edited" on ordinary pages

> Tending toward no for both, but willing to be convinced otherwise..
> [[merged|done]] --[[Joey]]