repomd tags question

The createrepo command provides for <distro> and <content> tags in 
repomd.xml.  My question is, what other repository or install related 
commands read these tags and make use of them?  Does yum?  Or are the 
tags provided for manual inspection and custom tools.  Other than the 
createrepo manpage I can't find any documentation suggesting how these 
tags are used once they exist in the repomd file.

Jon