----
+# compatability breaking changes
+
+Probably incomplete list:
+
+* Drop old `--getctime` option.
+* Remove compatability code in `loadindex` to handle old index data layouts.
+* Make pagespecs match relative by default? (see [[discussion]])
+* Flip wikilinks? (see [[todo/link_plugin_perhaps_too_general?]])
+* YADA format setup files per default?
+* Enable tagbase by default (so that tag autocreation will work by default).
+ Note that this is already done for wikis created by `auto-blog.setup`.
+* [[tips/html5]] on by default (some day..)
+* Remove support for old `.ikiwiki/comments_pending` from comment plugin.
+* Use yaml formatted setup files by default. (Not too compatability breaking
+ really.)
+
+In general, we try to use [[ikiwiki-transition]] or forced rebuilds on
+upgrade to deal with changes that break compatability. Some things that
+can't help with.
+
# future goals
* Conversion support for existing other wikis.