These are likely identifiers for the featured individual (Fibi) and the production region or studio style (Euro).
While the string itself looks like a technical label used by databases or file-sharing networks, it highlights an interesting intersection of Breaking Down the Syntax private240730fibieuroprivatedebutxxx10
To understand what a string like this represents, we can look at the common "scene" naming conventions used in digital circles: These are likely identifiers for the featured individual