Regarding coffee cup - this has been used the way it is since long before the wiki page was created. Which either means that the wiki is bad or that the tag needs a change of usage. I'm indifferent as to which route is taken but this probably warrants its own separate decision.
Kikimaru said:
Going by its wiki definition
"A type of mug that holds about 2 cups of hot coffee"
I propose to this alias so that it's easier to understand it stands for a large/double-sized mug.
My concern with this is more along the lines of if ALL large mugs should be given the coffee mug tag, which this alias would suggest. For instance, a large soup mug is not a coffee mug, and can be radically different in shape to anything coffee is normally drunk from.
We could maybe remove both paper_cup & coffee_cup by aliasing both to something like disposable_cup?
That would be certainly be an option, yes, and possibly better than the current situation. If we chose to go with the wiki definition of coffee cup then I'd be in favour of this.
"Papercup" returns 8,940k Google results, only 880k less than "Paper cup"
Also tea_cup -> teacup
Only because papercup returns a shedload of results that are actually finding "paper cup".
If you put the quotation marks around them to give only the things you are actually searching for, "papercup" gives 402k results (of which the top results are all names of companies), against 8490k for "paper cup".
Teacup, on the other hand, is an actual word.
Mug already implicates cup.
Which is all the more reason to put the implication to mug.
An implication of coffee mug to mug would give everything tagged with coffee mug the mug and cup tags as well. An implication to cup would only give them the cup tag. The implication should go to mug unless there are cases where a coffee mug is a cup but not a mug.