Je was op zoek naar: digraphs (Wels - Engels)

sorting digraphs
trefnu deugraffau

if letter counts are used, do they take account of digraphs?
os caiff llythrennau eu cyfrif, a ystyrir deugraffau?

in the absence of this, all instances of “ng” (and other potential digraphs) should be treated as actual digraphs (a).
os nad yw hyn i gyd ar gael, dylid trin pob enghraifft o “ng” (a deugraffau posibl eraill) fel deugraffau go iawn (a).