[[!comment format=mdwn
 username="kyle"
 avatar="http://cdn.libravatar.org/avatar/7d6e85cde1422ad60607c87fa87c63f3"
 subject="re: rationale"
 date="2020-03-09T22:17:51Z"
 content="""
> Is there a rationale for not having the option for preferred contents?

Hmm, I wouldn't be able to answer this myself, but digging around a
bit it looks like there used to be an `in=` option.  Here's the
rationale given in that commit:

```
CommitDate: Fri Oct 19 16:09:21 2012 -0400
40aab719dfe9c3bd240656c1ff387cad0ba8d96d

Replace \"in=\" with \"present\" in preferred content expressions

in= was problimatic in two ways. First, it referred to a remote by name,
but preferred content expressions can be evaluated elsewhere, where that
remote doesn't exist, or a different remote has the same name. This name
lookup code could error out at runtime. Secondly, in= seemed pretty useless.
in=here did not cause content to be gotten, but it did let present content
be dropped.

present is more useful, although \"not present\" is unstable and should be
avoided.
```

"""]]
