We are trying, but that's not very easy sometimes !

There are a lot of interesting points raised by people here. Especially the last one:
Is a Catalan a demonym  or/and ethnicity or/and nationality (i know that all the previous terms are themselves vaguely determined)? Can it be determined by blood or/and soil ? If so what are the current "rules"?

I mean, as our friend "CataloniaCoin" posed a supposedly "idiot-proof example" (i.e. something that doesn't need a lot of explanation and assumes that all the necessary assumptions, for the analysis of the statement, are common sense), of a Chinese guy in Catalonia, i would like to see a little bit clearer definition of a "Catalan" from the creators of the CataloniaCoin. If that even possible of course. 

From the current Statue of Autonomy (regional constitution), article 7:

(source: official English version http://www.parlament.cat/porteso/estatut/estatut_angles_100506.pdf)

See also https://ca.wikipedia.org/wiki/Condici%C3%B3_pol%C3%ADtica_de_catal%C3%A0 (in Catalan).