Blushing wrote:
No actual word begins with RD.
Unless if you include other languages. This topic isn't limited to English.
Also, you originally mentioned about conjuctions. Onboard is not an conjunction in English, it's an adverb or I'm not even sure what your education system tells you about English Grammar.
Conjunctions like 'and', 'but', 'if', etc., are supposed to connect clauses. So what you meant was to only permit words whose ending two letters can begin a new English word by itself.
On-Topic: Ordering.