Feasible?

But can people do this?

Can they disambiguate illocutionarily diverse expressions?

Or even assertions?

Or even identify titles, authors, and subjects?

Yes!

" ... the clinic's office manager (who never took Comp Sci 101) massaged it into shape using off-the-shelf software for writing Semantic Web pages ..." (Berners-Lee et al. 2001).

"Only 3.5% of Title fields, 3.7% of Description fields, and 3.5% of Keywords ... were incorrect" (Zhang and Jastram 2006 p 1121).

No!

"Effective use of such a formal representation requires the author to become a skilled knowledge engineer" (Marshall & Shipman, 2003).

"Trying to express implicit and fuzzy relationships in ways that are explicit and sharp doesn't clarify the meaning, it destroys it" (Shirky 2003).

"... the DC.Title element failed to adequately provide the title that most searchers would expect .... a 48% pass rate ... is extremely low" (Sokvitne 2000 p 8).

Valid XHTML 1.1!