Thomson Reuters have been awarded a patent for a "System and method for citation processing, presentation and transport and for validating references" that, in my eyes, looks very much like what BibTeX has been doing since 1985. If that were the case, my understanding is that BibTeX would constitute prior art and render the Patent invalid.
But I'm making these observations as a layperson with no background in law whatsoever. So perhaps my observation is wrong/incomplete or my conclusion is wrong/inaccurate (and I understand that only a court can give a legally binding answer to that)?
There is surely much to be said about the matter, so to formulate a clear question that can actually be answered, I'm looking at this from the perspective of a company that wants to sell a software using placeholders for citation processing in the manner that BibTeX or Endnote do (disclaimer: I do not own or work for such a company). The question, then, is: would it be legal to sell this software in the USA?
I suspect that this question may still be somewhat too broad since the answer obviously depends very much on what the software will actually do and how that compares to (a) the patent and (b) BibTeX. So, I'm offering the following two alternative specifications, in case this helps to give useful answers:
a) assume that the software uses the BibTeX system to process citations,
b) assume that although the software does not use the exact BibTeX system but its own way of constructing and parsing placeholders. However, the principle is still the same in that the software parses the manuscript for placeholders which are formatted according to predefined rules and which will trigger a database lookup to match corresponding title in order to then replace the placeholder with a reference to the title which is formatted according to predefined rules.