All the academic cross-referencing formats are pretty awful. None of them are particularly powerful and there's so many opinions about the correct way to do it, they become worthless.
Cross-referencing is done terribly.
A code that is subscript next to a word or phrase to link to a portal of that word
我在想-HTML中的“ A”標記用於引用-但大多數情況下，除了鏈接標題外，我們不包含適當的語義關係（但如果可以的話，我們可以使用的語義鏈接）。例如，Wikidata P是此類鏈接類型的列表（它們稱爲屬性）...
I'm thinking -- the "A" tag in HTML was meant for referencing -- but most of the time, we do not include a proper semantic relationship, other than link title (but we could, if we had a list of commonly used semantic links). For example, Wikidata P is a list of such link types (they call them properties)...
But then, URL itself as such was meant for referencing, so why shouldn't a URL include semantic link data.
And then, usually URLs are long, if you want to reference things in plain text (rather than hypertext).
These are certainly challenges in cross-referencing.