Briefly, the script works based on #thestrat developed by Rob Smith and the 1-2-3 bar script coded by @Crinklebine. Candle Type w/2Up + 2Dn is a "fork" of @Crinklebine's excellent indicator. I find the visualization of U-D-I-O (up/dn/inside/outside candles) easier to scan through 100's of charts than 1-2-3's. This is just personal preference, but they work based on the exact same principles. Performance is enhanced with a trend filter like @boardriderb's "TC" script or similar timeframe continuity filters based on the #thestrat developed by Rob Smith. I also prefer an ATR-based trailing stop; Rob recommends pSAR for trailing stops.
Together these indicators form a power system, but users are still responsible for their own trade management, entries & exits, risk profiles, stop loss, etc.
In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.