The saga of the different versions of RSS is a long and tragic story, with no less than 4 (Atom included) common, competing formats in use today. Luckily most clients support them all, so normal users should not need to worry.
Currently we use the following versions in WeatherAPI:
RSS is normally not parsed manually, but using a software client of which there are many. My personal favourite is NewsBlur, but you can find many others on the app stores for different platforms.
The RSS 1.0 format does not define more than a few terms, preferring instead to delegate this issue to external ontologies in different namespaces like Dublin Core.
Since we have not found any suitable ontology for some metadata, we are
forced to roll our own. These will be using the
No simple corresponding term to the RSS 2.0 “category” exists for 1.0, so we have to define our own. Sadly this means there is no way to filter on categories directly in off-the-shelf feed readers when using RSS 1.0.
—Geir Aalberg, 17 April 2020