RSS subscription and smart filtering to download only one type of same content

[spamme]

I use RSS to download some "content", which can be of type XXX or YYY, most of the times there is only one type but sometimes both are available. In the latter case I want only to download either the XXX or the YYY type but not both, because they are "exactly" the same. I wouldn't care if they would be quite small, but actually they are about 30GB each, so I would like to know, if there is a way to filter the RSS feed in a smart way to skip "content", which is "exactly" the same but of a different type.