(2016-05-31, 9:38 pm)eslang Wrote: なるほど！Thanks for the explanation. I think it helps me understand the term a little better now.
It seems that the word "rare" depends on how the user relates to it, which is from their learning perspective?
Out of curiosity, when people refer to "obscure" kanji, is it the same as "rare" kanji?
Also, I came across some sites that have ratings, and somehow, the word "different" kanji is being used interchangeably with "unique" kanji, or even "unusual" kanji at other times. Does it mean "unknown" kanji in such situation or refer to something else, such as "different" from the database (sample) size?
Well, people use words in all kinds of different ways so you can't rely on these terms as having any fixed meaning.
With that warning, I'd say that people talk about 'rare' or 'uncommon' kanji to mean kanji that are in general use, but not seen often.
'obscure' kanji is something that only a scholar or specialist would know - antiquated kanji or kanji used only in a certain field.
'different' or 'unusual' kanji most often refers to spelling words with varying kanji, but in another context maybe 'unusual' is being used the same way we used 'rare' in this thread. (Sometimes two words 'have the same reading but different kanji', while at other times one word can be written with more than one kanji... the 'usual' way and one or more 'unusual' ways.) Still, I wouldn't be surprised to see these words used instead of 'rare' or 'obscure' for the meanings I gave those.
I don't know what a 'unique' kanji would be unless it was referring to someone's calligraphy style, or maybe to a made-up faux kanji... unless you're analyzing a body of work, then you might talk about the count of how many 'unique kanji' appear within a book, meaning your counting how many different kanji appeared and not counting repetitions... you'll have to work that one out from context.
(And I just used 'different kanji' differently from how I described it... hmmm.)
An 'unknown' kanji usually means unknown to the person speaking, but depending on context it could mean an illegible kanji, a blank in a crossword puzzle or the like, or even just be used instead of 'obscure'.
Still, none of these are well-defined terms, so as they say, your mileage may vary. Context will be your friend, hopefully, or else you can ask for clarification.