Thanks for historically locking:
But, is it strictly necessary?
I can foresee a time in the not-too-distant future when HTML Modules are finally completed and become a recommended standard, at which point an answer (either from me or another Webmasters SE member) confirming as much will be the definitive, accepted answer.
This is the primary reason why, to date, I have not accepted an answer on the question.
All views welcome.
I trust that, given that:
- the question is pertinent to Webmastering, focusing on which browsers support (or have supported in the past) client-side functionality to enable importing markup into a current document
- the question has 17 upvotes
it will generally be quite welcome as an open question on Webmasters SE.