There are some templates which are partials and so can't show up properly in the template library without the surrounding context, or being included in their parent.

e.g. blocks/rss_client/templates/item.mustache

We could do with a way to indicate that these templates should:
a) Not show up in the template library
b) Not be expected to be valid html by cibot

Perhaps we could add some metadata such as 'this partial is part of x template' to achieve that, or any other ideas.