[TYPO3-extbase-kickstarter] blog_example: why (and how) reciprocal refs between blog and post repo's?

[GallupCurrent Support]

In the Blog example there is a reference in the blog table to the posts
table... which seems natural, but then there is also a reference to the blog
table in the posts table... which seems odd to me. When will a post ever
appear in more than one blog? Not only that, but how were the repositories
set up for this... I don't think the kickstarter can handle it.

I came across this when attempting to create just such a structure in the
kickstarter[1]. I have trails and trail systems... in some cases trails can
be in two trail systems, thus there might be a reason for a trails reference
(foreign key) in the trailSystem table and vise versa. I attempted to do
this in the kickstarter, but it does not seem to have set up everything
properly, and I am not sure where to fix the model.

Any insight?

[1] http://www.livegallup.com/fileadmin/img/kick-fce-illus.png