My humble opinion about a divergence is this:
Usually a divergence indicates the fact that although the current peak (we shall take an uptrend with a bearsih div as an example) is higher than the previous, the momentum is actually lower, meaning that the power of bulls has actually diminished, there was a lower enthusiasm for a move. The effect of the divergence should not be a reversal of the trend as many people see it, but a mere correction. When you play the divergence, you should know that, and not swing for any fences. Just place the stop above the last peak as when the peak is "taken" your divergence is not valid anymore, and when the trade moves in your favour, quickly trail your stop.
Now, coming back to the divergence itself. The best indicator for a divergence is an indicator derived from moving averages, which are the closest thing to price and measure speed as we;; as amplitude in a linear manner. When they move far apart, they indicate that momentum is increasing. A good indicator for divergence is MACD Histogram, with which you can rate the power of individual swings inside a trend. MACD lines rate the power of different mini-trends, but can't gauge the swings inside them.
Stochastics is also a momentum indicator, but it does not analyze the market in a linear fashion, like the MA-derived indicators, but by looking back and comparing ranges. For me, this is a little empirical to be trusted, BUT, it works, and i'll tell you where it works. First of all, because of the calculation formula, it works on daily charts of instruments that are exchange based. Second, it works on charts that show a constant flow, and are not disrupted by periods of really low volatility, followed by periods of madness and then disrupted again. It doesn't work however on intraday charts. The idea is that the more low-level you get with your timeframe, the more primitive the indicators should be, or you should rely heavy on chart patterns.
So divergence of Stochastics works on the above mentioned charts. Hidden divergences..hmm... anything "hidden" doesn't sound good to me.
