Dublin Core Uses

There are several Dublin Core Uses... but what are the models behind them? Are they the same? Are they different? If they are different then does this mean that Dublin Core is more like a brand name than a metadata standard?

RSS: https://web.resource.org/rss/1.0/modules/dcterms/
HTML: https://www.dublincore.org/specifications/dublin-core/dcq-html/; https://www.dublincore.org/specifications/dublin-core/dc-html/
HTML: https://www.hjp.at/doc/rfc/rfc2731.html ; https://www.ietf.org/rfc/rfc2731.txt

Note that in https://www.ietf.org/rfc/rfc2731.txt they use DC1.0

When another application profile "borrows" the DC property/term/element... how do they borrow it? https://exiv2.org/tags-xmp-dwc.html