Single prints are a market-profile (TPO) concept: price levels that were touched during only one 30-minute bracket of the session — a single letter/print in that row of the profile, with no other time period trading there.

They matter because they mark fast, one-sided movement — price ripped through those levels so quickly that only one time bracket printed, leaving no acceptance or two-way auction. That signals an imbalance, so single-print zones tend to act as support/resistance on a revisit and often get "filled in" (retested) later as the market returns to areas it skipped.

• Builds the profile from a finer timeframe (1m) aggregated into 30m brackets, NQ/ES tick-stepped.

• Detection is run-based and body-only: it finds consecutive rows with a count of exactly 1, groups them into runs, and only draws a run if it's bounded by 2+ print rows on both sides — which excludes the profile's natural high/low tails (those aren't true single prints, just the edges).

• Draws one line per run at the first-printed edge, extended to the price scale, and handles mitigation (freeze/recolor or delete when price trades back through).

So it isolates genuine skipped-price gaps inside the profile rather than flagging every high and low.