Unclosed windows signal continuation of the trend. Basically, dojis reflect indecision which makes sense since the market closed unchanged for the day after trading significantly higher and lower intraday. If you see two or more doji lines within a short time in a market where this normally does not occur, then a sttrong move is possible. Double dojis may foretell an increase in market volatility. They could benefit from premium expansion based on increased volatility and a significant price move.
Doji days can become support or resistance, usually on a short-term basis.
And a series of three doji lines after a prolonged move could signal a rate and important top or bottom. However, their significance remains the same as other dojis. A third edition will cover other candle patterns with intriguing names like tweezers, two crows and the three Buddhas.