A rule of thumb for writing Welsh place names is that they should be spelled according to the standard language and not the local dialect form (though there are many instances of names showing local traits rather than a standard version - Machynlleth for Machynllaith, Caerdydd for Caerdyf etc. An initial 'c' in a final syllable in the Gwentian - Gwenhwyseg dialect is often a devoiced form of 'g', and such is the case here. An initial 'r' is generally a deaspirated 'rh' in the dialect, but this is not the case here. Since in South Wales 'u' and 'i' no longer represent different vowel sounds (though in North Wales these spellings DO show different vowels) in spelling 'i' might be used instead of the historically correct spelling with 'u'.