I agree that discussions about what something "ought" to be called are sometimes superfluous. However, agreeing on the definitions of terms is rarely superfluous - in fact, it's usually critical to a useful discussion and good decisions. So, I start there:

Tick: Timestamp, Bid, and Ask provided whenever one of the latter 2 changes in live trading; or provided as historical data from live trading. (Or I suppose could be made up to simulate future trading...)

Bar: Timestamp, Open, Close, High, and Low built from the Ticks of whatever the Bar's historical time period is, possibly ending with the most recent live data, Open coming from the last Tick prior to the start of the time period. Also called Candle.

Is this correct? Is there any other useful term to define?

Using those definitions, my understanding is that Zorro's provided history files are 1 minute Bars built from the historical Ticks - is that correct?

Returning to pipclown's original question, he saw a preponderance of High==Open and Low==Close for EUR/USD in the 1st 1/2 of 2007. GBP/USD shows the same thing, but AUD/USD does not - why the difference?

Additionally, for EUR/USD the preponderance persists through 2010 but vanishes beginning with 2011 - why?

Thanks.