The if-then tag seems a bit pointless, but is being used. Could we please either:
Burninate it; or
Make it a synonym for if-statement?
(This came to my attention through https://stackoverflow.com/review/suggested-edits/2285785 where user Dariusz was giving the tag if-then the tag excerpt "do not use this tag; use
if-statement which is more general". This seems sensible to me.)