Broken links to docs pages about specific features
This is a content issue that affects multiple pages in the same way...
For example, on https://civicrm.org/features/contacts go to the bottom of the page and find a link labeled "CiviCRM Book:" which points to
http://book.civicrm.org/user/current/organising-your-data/contacts/
This link is broken and probably has been for about a year. It needs to be updated to point to the correct page in the User Guide.
The same needs to happen for (I think) all other "features" pages like this one. There are, at least, a few cases of it. (Haven't looked through all pages)