Mbo - thought the "O" prefix meant "grandson of". and "M', Mc or Mac" meant "son of". Thirty or so years ago Mother Jones mag (i think) proposed Co and Cos as singular and plural generic pronouns, but it never caught on. I find that when I seek to be deliberately gender-neutral, I usually use the word "their", but sometimes seem forced to take liberties with the singular/plural rules. Use of collective nouns, and singular/plural agreement with associated verbs, is an area of disagreement between conventional American and European usage in English; e.g.; "the government are" vs "the government is". All this sensitivity stuff can itself be rather insensitive, not to mention unnecessarily confusing.