What's with the backslashes at the start of words in YAML doc files?

[Eric Promislow]

The problem:

Files like
<ruby-install>/gems1.8/doc/actionpack-2.2.2/ri/ActionController/
AbstractRequest/content_type-i.yaml

contain text like this:

body: For backward compatibility, the post \format is extracted ...

What's with the backslash at the start of "format"?

I'm pulling out any backslashes that match /\s\\\w/, but I'm wondering
what
the backslash is for. yaml.org has been down all day.

Thanks,
Eric