# Order blocks: read zones and invalidation precisely Understand Core internal and swing order blocks, distinguish a touch from a break, and compare High/Low and Close mitigation with numbers. Canonical: https://getphantomflow.com/docs/order-blocks Updated: 2026-09-09 Author: Phantom Flow documentation An order block in Core is a price zone derived from the structure module's historical price analysis. It provides a marked range to inspect. It is not direct evidence of a particular institution's orders, a live order book, or unfilled orders waiting at that price. Core distinguishes internal and swing order blocks. Internal Order Blocks starts enabled in the reviewed Core defaults, while Swing Order Blocks starts disabled. A chart with only internal zones is therefore not necessarily missing data. ## Read the box before naming the event Record whether a zone is bullish or bearish, whether it belongs to internal or swing structure, and its upper and lower prices. Then describe what price actually did: approached the range, entered it, or crossed its far boundary. These are different observations. In particular, the Core alert names containing OB Breakout refer to the zone's break condition. They do not mean a new block has formed, and they are not generic notifications for the first touch of a zone. ## High/Low versus Close mitigation Order Block Mitigation selects the price source used to test a break. High/Low uses the candle extremes; Close uses the close series. The reviewed default is High/Low. Consider a hypothetical bullish zone from 98 to 100. A candle trades down to 97.8 and ultimately closes at 99. Under High/Low mitigation, the low has crossed below the zone's lower boundary. Under a closing-price comparison at the completed bar, 99 has not crossed below 98. For a bearish zone from 110 to 112, a high of 112.4 crosses the upper boundary under High/Low. A completed close of 111 stays within the zone under a closing-price comparison. The source checks for movement beyond the boundary, so exact equality is not the same as crossing beyond it. These examples explain the setting; they do not define an entry, stop, or exit plan. ## Close does not mean confirmed bars only While a candle is open, its close series changes with current price. Selecting Close as the mitigation source does not add a universal closed-bar confirmation rule to Core. Capture the finished candle and the alert frequency when comparing an intrabar break with a later chart. The [confirmation guide](/docs/repainting-and-confirmation) covers this distinction. It matters when a zone seems to disappear during a candle and the final screenshot tells a different story. ## Why two charts show different zones Compare script version, symbol and exchange, timeframe, enabled block type, Order Block Filter, mitigation choice, and the number of displayed blocks. Core offers an ATR or cumulative mean range filter. Filters and display limits can change which boxes you see, so a missing old box is not sufficient evidence that the original zone never existed. For a reproducible support report, include a screenshot before the event and one after, with the zone prices and timestamp visible. Use [Core alerts](/docs/core-alerts) to match the notification name to the event you are investigating. ## Related articles - [BOS vs CHoCH: read structure at the right scale](https://getphantomflow.com/docs/bos-vs-choch) - [Create and troubleshoot Phantom Flow Core alerts](https://getphantomflow.com/docs/core-alerts) - [Repainting, bar confirmation, and higher-timeframe timing](https://getphantomflow.com/docs/repainting-and-confirmation) Educational documentation. Phantom Flow visualizes chart information and provides alerts. It does not execute trades or guarantee results.