Crisis Rail

Clearly () it's O gauge, pronounced "Oh gauge", not "Zero gauge" or "nought gauge" and OO is two O characters pronounced "Double Oh".

The Gauge O guild spell their name with an "Oh" and Peco sell "O gauge" with an "Oh" products...

P.S. Rudd have yellow eyes...

(Takes cover.)

Yes, but the pronunciation of 0 in a phone number is usually given phonetically as as 'Oh' hence verbally the gauge being referred to in the same way as if it were O Gauge.  However, I believe the correct (or at least original) written form is numeric.  However, I realise that along the way, both seem to be used interchangeably with O becoming more popular in the same way as language evolves over time.  I think that is because the more recent gauges have used alphabetic characters (T, Z, N, S etc).  Interestingly, I've noticed that the Americans tend to refer to their most popular scale as HO, while the Europeans tend to refer to their most popular scale as H0.  I'm European.

Did you mean 'Acho (Ash-O)' for H0? If yes, that's the way the club members pronounce here in the deepest, darkest corner of eastern France. This should have been started as a topic - have a feeling it would have developed a nice head of froth!